For a complete list of countries, also see List of countries or the Countries tree. For flags see politics section (under Society and social sciences).

Arctic — League of Nations — List of members of the Commonwealth of Nations by date joined — United Nations

For articles on African topics, see the Africa tree

List of African countries — Algeria — Angola — Benin — Botswana — Burkina Faso — Burundi — Cameroon — Cape Verde — Central African Republic — Chad — Comoros — Republic of the Congo — Democratic Republic of the Congo — Côte d'Ivoire — Djibouti — Egypt — Equatorial Guinea — Eritrea — Ethiopia — Gabon — The Gambia — Ghana — Guinea — Guinea-Bissau — Kenya — Lesotho — Liberia — Libya — Madagascar — Malawi — Mali — Mauritania — Mauritius — Mayotte — Morocco — Mozambique — Namibia — Niger — Nigeria — Réunion — Rwanda — Saint Helena — São Tomé and Príncipe — Senegal — Seychelles — Sierra Leone — Somalia — South Africa — Sudan — Swaziland — Tanzania — Togo — Tunisia — Uganda — Western Sahara — Zambia — Zimbabwe

Abidjan — Abuja — Accra — Addis Ababa — Algiers — Antananarivo — Asmara — Bamako — Bangui — Banjul — Bloemfontein — Brazzaville — Cairo — Cape Town — Conakry — Cotonou — Dakar — Dar es Salaam — Freetown — Harare — Hargeisa — Johannesburg — Kampala — Khartoum — Kigali — Kinshasa — Libreville — Lilongwe — Lomé — Luanda — Lusaka — Maputo — Mogadishu — Monrovia — N'Djamena — Nairobi — Nouakchott — Ouagadougou — Port Louis — Pretoria — Rabat — Suburbs of Johannesburg — Tripoli — Tunis — Windhoek — Yamoussoukro — Yaoundé

Africa — Ascension Island — Cabinda (province) Congo River — Huambo (province) — Niger River — Nile — Suez Canal — Tindouf Province — Zambezi

For articles on Antarctic topics, see the Oceania & Antarctica tree
Antarctica — Antarctic Treaty System — Bouvet Island — French Southern and Antarctic Lands — Grytviken — Heard Island and McDonald Islands — South Georgia and the South Sandwich Islands — Southern Ocean

For articles on Asian topics, see the Asia tree

List of Asian countries — Afghanistan — Armenia — Azerbaijan — Bahrain — Bangladesh — Bhutan — British Indian Ocean Territory — Brunei — Burma, see Myanmar — Cambodia — China (historical, also see PR China and Rep. China) — People's Republic of China — Republic of China — Christmas Island — Cocos (Keeling) Islands — Cyprus — Georgia — Hong Kong — India — Indonesia — Iran — Iraq — Israel — Japan — Jordan — Kazakhstan — North Korea — South Korea — Kuwait — Kyrgyzstan — Laos — Lebanon — Macau — Malaysia — Maldives — Mongolia — Myanmar — Nepal — Oman — Pakistan — Palestinian National Authority — Philippines — Qatar — Saudi Arabia — Singapore — Sri Lanka — Syria — Taiwan, see Republic of China — Tajikistan — Thailand — East Timor — Turkey — Turkmenistan — United Arab Emirates — Uzbekistan — Vietnam — Yemen

Abu Dhabi — Almaty — Amman — Ankara — Ashgabat — Astana — Baghdad — Baku — Bangalore — Bangkok — Beijing — Beirut — Bishkek — Canton (city), also called Guangzhou — Chennai — Colombo — Damascus — Delhi — Dhaka — Dili — Doha — Dubai — Dushanbe — Erevan, see Yerevan Gangtok — Guangzhou — Hanoi — Ho Chi Minh City — Hong Kong — Islamabad — Jakarta — Jerusalem — Kabul — Karachi — Kathmandu — Kolkata — Kotte — Kuala Lumpur — Kuwait City — Manama — Manila — Mumbai — Muscat, Oman — Naypyidaw — New Delhi — Nicosia — Osaka — Phnom Penh — Putrajaya — Pyongyang — Riyadh — San‘a’ — Seoul — Shanghai — Taipei — Tashkent — Tbilisi — Tehran — Tel Aviv — Thimphu — Tokyo — Ulan Bator — Vientiane — Yerevan

Akrotiri and Dhekelia — Kabul Province — Laghman Province — Siberia

Goa — Kerala — Kochi (India) — Malwa (Madhya Pradesh) — Sikkim — West Bengal

Amur — Asia — Euphrates — Ganges River — Grand Canal of China — Gyeongju — Geography of India — Indus River — Isan — Jordan River — Krakatoa — Mekong — Mount Pinatubo — Taiwan — Tibet — Tigris — Yangtze River — Yenisei River — Yellow River

For articles on European topics, see the Europe tree

List of European countries — List of European Union member states by accession — Åland — Albania — Andorra — Austria — Belarus — Belgium — Bosnia and Herzegovina — Bulgaria — Croatia — Czech Republic — Denmark — England — Estonia — Faroe Islands — Finland — France — Germany — Gibraltar — Greece — Guernsey — Hungary — Iceland — Republic of Ireland — Isle of Man — Italy — Jan Mayen — Jersey — Latvia — Liechtenstein — Lithuania — Luxembourg — Republic of Macedonia — Malta — Moldova — Monaco — Montenegro — Netherlands — Northern Ireland — Norway — Poland — Portugal — Romania — Russia — San Marino — Serbia — Scotland — Slovakia — Slovenia — Spain — Svalbard — Sweden — Switzerland — Ukraine — United Kingdom — Vatican City — Wales

Aarhus — Amsterdam — Antwerp — Athens — Barcelona — Basel — Bath, Somerset — Belfast — Belgrade — Berlin — Berne — Birmingham — Bristol — Bologna — Bratislava — Brussels — Budapest — Bucharest — Chişinău — Cologne — Copenhagen — Dresden — Dublin — Düsseldorf — Edinburgh — Frankfurt — Geneva — Genoa — Glasgow — Gothenburg — The Hague — Hamburg — Helsinki — Istanbul — Kiev — Kishinev, see Chişinău — Leeds — Lille — Lisbon — Liverpool — Ljubljana — London — Luxembourg (city) — Lviv — Lyon — Madrid — Manchester — Marseille — Milan — Minsk — Moscow — Munich — Novgorod, see Velikiy Novgorod — Osijek — Oslo — Paris — Peterborough — Podgorica — Prague — Reykjavík — Riga — Rijeka — Rome — Rostov — Rotterdam — Saint Petersburg — Sarajevo — Sheffield — Skopje — Sofia — Split — Stockholm — Stuttgart — Sunderland — Tallinn — Tirana — Turin — Utrecht (city) — Valletta — Velikiy Novgorod — Vienna — Vilnius — Warsaw — Zagreb — Zürich

Abkhazia — British Isles (terminology) — City status in the United Kingdom — Crimea — Danube — Dnieper River — Dorset — Eldfell — Europe — Geography of Ireland — Kosovo — Moorgate — National parks of England and Wales — Piccadilly Circus — Rhine — River Thames — Rondane National Park — Surtsey — Volga River

For articles on North American topics, see the North America tree

List of North American countries — Anguilla — Antigua and Barbuda — Aruba — The Bahamas — Barbados — Belize — Bermuda — British Virgin Islands — Canada — Cayman Islands — Costa Rica — Cuba — Dominica — Dominican Republic — El Salvador — Greenland — Grenada — Guadeloupe — Guatemala — Haiti — Honduras — Jamaica — Martinique — Mexico — Montserrat — Navassa Island — Netherlands Antilles — Nicaragua — Panama — Puerto Rico — Saint Kitts and Nevis — Saint Lucia — Saint-Pierre and Miquelon — Saint Vincent and the Grenadines — Trinidad and Tobago — Turks and Caicos Islands — United States — United States Virgin Islands

List of Canadian provinces and territories by area — List of Canadian provinces and territories by population — Alberta — British Columbia — Manitoba — New Brunswick — Newfoundland and Labrador — Northwest Territories — Nova Scotia — Nunavut — Ontario — Prince Edward Island — Quebec — Saskatchewan — Yukon — Calgary — Edmonton — Montreal — Ottawa — Quebec — Toronto — Vancouver

Ann Arbor, Michigan — Atlanta, Georgia — Baltimore, Maryland — Boston, Massachusetts — Chicago — Cleveland, Ohio — Columbus, Ohio — Dallas, Texas — Denver, Colorado — Detroit, Michigan — Houston, Texas — Kansas City, Missouri — Las Vegas, Nevada — Los Angeles, California — Louisville, Kentucky — Madison, Wisconsin — Miami, Florida — Minneapolis, Minnesota — Newark, New Jersey — New York City — Philadelphia — Richmond, Virginia — San Francisco, California — San Jose, California — Seattle, Washington — Topeka, Kansas — Washington, D.C.

List of areas in the National Park System of the United States — Bryce Canyon National Park — Carlsbad Caverns National Park — Craters of the Moon National Monument and Preserve — Death Valley National Park — Glacier National Park (US) — Mount Rushmore — Mount St. Helens — Redwood National and State Parks — Shoshone National Forest — Yellowstone National Park — Yosemite National Park — Zion National Park

Alabama — Alaska — Arizona — Arkansas — California — Colorado — Connecticut — Delaware — Florida — Georgia (U.S. state) — Hawaii — Idaho — Illinois — Indiana — Iowa — Kansas — Kentucky — Louisiana — Maine — Maryland — Massachusetts — Michigan — Minnesota — Mississippi — Missouri — Montana — Nebraska — Nevada — New Hampshire — New Jersey — New Mexico — New York — North Carolina — North Dakota — Ohio — Oklahoma — Oregon — Pennsylvania — Rhode Island — South Carolina — South Dakota — Tennessee — Texas — Utah — Vermont — Virginia — Washington — West Virginia — Wisconsin — Wyoming

Colorado River — Columbia River — Erie Canal — List of U.S. states by date of statehood — Mackenzie River — Mauna Loa — Mississippi River — Missouri River — Niagara Falls — North America — Saint Lawrence Seaway

Basseterre — Belmopan — Bridgetown — Guatemala City — Havana — Kingston, Jamaica — Managua — Mexico City — Panama City — Port-au-Prince — Port of Spain — San José, Costa Rica — San Juan, Puerto Rico — San Salvador — Santo Domingo — St. John's, Antigua and Barbuda — Tegucigalpa — Tijuana

For articles on topics relating to Oceania, see the Oceania & Antarctica tree

List of Oceanian countries — American Samoa — Australia — Christmas Island — Cook Islands — Federated States of Micronesia — Fiji — French Polynesia — Guam — Kiribati — Marshall Islands — Micronesia, see Federated States of Micronesia — Nauru — New Caledonia — New Zealand — Niue — Norfolk Island — Northern Mariana Islands — Palau — Papua New Guinea — Pitcairn Islands — Samoa — Solomon Islands — Tokelau — Tonga — Tuvalu — Vanuatu — Wallis and Futuna — Baker Island — Howland Island — Jarvis Island — Johnston Atoll — Kingman Reef — Midway Atoll — Palmyra Atoll — Wake Island

Adelaide — Brisbane — Auckland — Canberra — Hagåtña, Guam — Melbourne — Nouméa — Nuku'alofa — Papeete — Perth — Port Moresby — Saipan — Suva — Sydney — Wellington — Yarralumla, Australian Capital Territory

Australian Capital Territory — New South Wales — Northern Territory — Queensland — South Australia — Tasmania — Victoria (Australia) — Western Australia

Caroline Island — The Catlins — Darling River — Great Barrier Reef — Lake Burley Griffin — Murray River — Oceania

For articles on South American topics, see the South America tree

List of South American countries — Argentina — Bolivia — Brazil — Chile — Colombia — Ecuador — Falkland Islands — French Guiana — Guyana — Paraguay — Peru — Suriname — Uruguay — Venezuela

Asunción — Bogotá — Brasília — Buenos Aires — Caracas — Georgetown, Guyana La Paz — Lima — Montevideo — Oranjestad, Aruba — Quito — Rio de Janeiro — San Francisco de Quito, see Quito Santiago, Chile — São Paulo — Stanley, Falkland Islands — Valparaíso

Andes — Buenos Aires Province — Cape Horn — South America — Amazon River

Neil Armstrong — Christopher Columbus — Ferdinand Magellan — Marco Polo

For articles relating to atmospheric sciences, see natural sciences.

Geography — City — Climate — Continent — Desert — Country — Glacier — Global city — List of countries — List of lakes — List of rivers by length — List of sovereign states — List of world's largest lakes — Mountain — River — Sea

Note:Rivers and canals have been listed above (by continent).

General — Arctic Ocean — Atlantic Ocean — Black Sea — Caribbean Sea — Indian Ocean — Mediterranean Sea — Pacific Ocean — Southern Ocean

Africa — Lake Chad — Lake Tanganyika — Lake Victoria — (3 articles)

Antarctica — Lake Vostok

Asia — Aral Sea — Lake Baikal — Bay of Bengal — Caspian Sea — Dead Sea — Issyk Kul — Lake Toba — Persian Gulf — Red Sea — Sea of Galilee — South China Sea — Strait of Malacca

Europe — Baltic Sea — English Channel — North Sea

North America — Great Lakes — Great Salt Lake — Gulf of Mexico — Hudson Bay — Lake Mead — Lake Powell — Lake Superior — Lake Tahoe

South America — Lake Titicaca

Earth science — Geology

1980 eruption of Mount St. Helens — 2004 Indian Ocean earthquake — Avalanche — Cretaceous–Tertiary extinction event — Fossil — Geology of the Grand Canyon area — Iron — History of Earth — Mauna Loa — Natural disaster — Ocean — Oceanography — Plate tectonics — Soil — Volcano

Mineral — Rock (geology)

Ammolite — Diamond— Fossil fuel — Petroleum — Turquoise

Acid rain — Climate change — Earth's atmosphere — Global warming — Rain — Rainbow — Retreat of glaciers since 1850 — Water

Meteorology — Weather — Tornado

1928 Okeechobee Hurricane — 2005 Atlantic hurricane season — Cyclone Tracy — Eye (cyclone) — Galveston Hurricane of 1900 — Great Lakes Storm of 1913 — Hurricane Camille — Hurricane Dennis — Hurricane Floyd — Hurricane Gloria — Hurricane John (1994) — Hurricane Katrina — Hurricane Mitch — Storm surge — Typhoon Tip (1979)— Tropical cyclogenesis — Tropical cyclone — Tropical Storm Allison

Norman Borlaug — Charles Darwin — Georg Forster — Hippocrates — Athanasius Kircher — Carolus Linnaeus — Barbara McClintock — Gregor Mendel — Louis Pasteur — Alfred Russel Wallace — Michael Woodruff

Biology

Anatomy — Animal— Aquarium— Biological reproduction — Biotechnology — Botany — Cell (biology) (also see section below) — Cladistics— Cytogenetics — Death — DNA — DNA repair— Ecology — Eukaryote — Fossil — Genetics — Human Genome— Life — Metabolism — Organism — Plant — Protein — Scientific classification — Sequence alignment — Virus

Cell (biology)

Cell nucleus — Cell wall — Chloroplast — Chromatophore— Embryonic stem cell — Endoplasmic reticulum — Golgi apparatus — Mitochondrion — Photosynthetic reaction centre — Red blood cell‎ — Ribosome — Stem cell — Vacuole — White blood cell‎

Environmental threats to the Great Barrier Reef — Minamata disease

Abortion — Birth control — Creation-evolution controversy — Cretaceous–Tertiary extinction event — Evolution — Menstrual cycle — Sex

Health — Medicine

Acetaminophen, see paracetamol — Addiction — AIDS — Albinism — Allergy — Alzheimer's disease — Asperger's syndrome — Asthma — Attention-deficit hyperactivity disorder — Autism — Autostereogram — Blindness — Cancer — Cholera — Circulatory system — Clinical depression — Color blindness — Cystic fibrosis — Cannabis (drug) — Chagas disease — Diabetes mellitus — Disease — Down syndrome — Duchenne muscular dystrophy — Ebola‎ — Fetal Alcohol Spectrum Disorder — Haemophilia — Hepatitis A — Hepatitis B — Hepatitis C — Hepatitis E — Herpes zoster — HIV — HPV, see Human papillomavirus — Human papillomavirus — Huntington's disease — Influenza — Insulin — Keratoconus — Klinefelter's syndrome — Lesch-Nyhan syndrome — Life expectancy — Lung cancer — Lyme disease — Malaria — Médecins Sans Frontières — Meningitis — Minamata disease — Multiple sclerosis — Myers-Briggs Type Indicator — Myocardial infarction — Nanomedicine — Nutrition — Osteopathic medicine in the United States — Paracetamol — Phenylketonuria — Pneumonia — Prostate cancer — Rabies — Sexually transmitted disease — Shingles, see Herpes zoster — Sickle-cell disease — Smallpox — Stroke — Syphilis — Thalassemia — Tay-Sachs disease — Tooth development — Tooth enamel — Tourette syndrome — Tuberculosis — Turner syndrome — Weight training — Yellow fever

Also see specific animal groups below

Animal

Fauna of Australia

Nervous system — Action potential — Brain — Cerebellum — Chemical synapse

Dinosaur — List of dinosaurs

Albertosaurus — Amphicoelias — Ankylosaurus — Archaeopteryx — Compsognathus — Cretaceous–Tertiary extinction event — Diplodocus — Heterodontosauridae — Iguanodon — Psittacosaurus — Scelidosaurus — Stegosaurus — Thescelosaurus — Triceratops — Tyrannosaurus — Velociraptor

Mammal

Alpaca — Bear — Cat — Dog — Elephant — Gray Wolf — Guinea Pig — Human — Homo floresiensis — Island Fox — Mixed-breed dog — Platypus — Ring-tailed Lemur — Short-beaked Echidna — Tasmanian Devil

Whales: Whale — Blue Whale — Exploding whale — Humpback Whale — Orca — Right whale — Sperm Whale — Whale song

Bird

Albatross — Arctic Tern — Bald Eagle — Common Raven — Elfin-woods Warbler — Emu — Galah — Kakapo — Kererū — Mourning Dove — Parrot — Procellariidae — Senegal Parrot — Seabird.

Reptile

Alligator — Crocodile — Marginated Tortoise — Komodo Dragon — Snake — Turtle

Amphibian

Frog — Australian Green Tree Frog (White's Tree Frog) — Cane Toad — Olm

Fish

Shark

Antarctic krill — Caterpillar — Coconut crab — Cochineal — Insect — Krill — Myxobolus cerebralis — Shrimp farm — Spider.

Botany — Plant

Flower — History of saffron — Leaf — Marchantiophyta — Plant physiology — Pollination — Root — Saffron — Seed — Trade and usage of saffron — Tree

Fungus

Mushroom — Lichen — Yeast

Microorganism

Archaea — Bacteria — Helicobacter pylori

For groups not specifically listed above Algae

List of elements by name — List of elements by symbol

Actinium — Aluminium — Americium — Antimony — Argon — Arsenic — Astatine — Barium — Berkelium — Beryllium — Bismuth — Bohrium — Boron — Bromine — Cadmium — Caesium — Calcium — Californium — Carbon — Cerium — Chlorine — Chromium — Cobalt — Copper — Curium — Darmstadtium — Dubnium — Dysprosium — Einsteinium — Erbium — Europium — Fermium — Fluorine — Francium — Gadolinium — Gallium — Germanium — Gold — Hafnium — Hassium — Helium — Holmium — Hydrogen — Indium — Iodine — Iridium — Iron — Krypton — Lanthanum — Lawrencium — Lead — Lithium — Lutetium — Magnesium — Manganese — Meitnerium — Mendelevium — Mercury (element) — Molybdenum — Neodymium — Neon — Neptunium — Nickel — Niobium — Nitrogen — Nobelium — Osmium — Oxygen — Palladium — Phosphorus — Platinum — Plutonium — Polonium — Potassium — Praseodymium — Promethium — Protactinium — Radium — Radon — Rhenium — Rhodium — Roentgenium — Rubidium — Ruthenium — Rutherfordium — Samarium — Scandium — Seaborgium — Selenium — Silicon — Silver — Sodium — Strontium — Sulfur — Tantalum — Technetium — Tellurium — Terbium — Thallium — Thorium — Thulium — Tin — Titanium — Tungsten — Ununbium — Ununhexium — Ununoctium — Ununpentium — Ununquadium — Ununtrium — Uranium — Vanadium — Xenon — Ytterbium — Yttrium — Zinc — Zirconium

Acetic acid — Aluminium chloride — Ammonia — Carbon dioxide — Ethanol — Hydrochloric acid — Hydrogen peroxide — Iron(III) chloride — Raney nickel — Sodium chloride — Sodium hydroxide — Sodium sulfate — Sulfuric acid — Toluene — Zinc chloride

Cannabis (drug) — Lysergic acid diethylamide — Medicine — Paracetamol (acetaminophen)

Marie Curie — Michael Faraday — Antoine Lavoisier — Dmitri Mendeleev — Alfred Nobel — Linus Pauling

Chemistry

Acid — Acid rain — Alchemy — Alcohol — Atom — Chemical element — Fire — Fuel — Inorganic chemistry — Metal — Molecule — Organic chemistry — Periodic table (large version) — Periodic table — Phase (matter)

Minamata disease — Pollution

Brass — Glass — Steel — Wood

Copernicus — Marie Curie — Galilei, Galileo — Einstein, Albert — List of scientific publications by Albert Einstein — Hawking, Stephen — Kepler, Johannes — Maxwell, James Clerk — Newton, Isaac — Oppenheimer, Robert — Planck, Max — Ptolemy — Sagan, Carl — Teller, Edward — Tesla, Nikola — Watt, James — E. P. Wigner

Astronomy —

Amateur astronomy — Amateur radio — Astrophysics Data System — Big Bang — Binary star — Black hole — Cat's Eye Nebula — Ceres (dwarf planet) — Comet — Comet Hale-Bopp — Comet Hyakutake — Comet Shoemaker-Levy 9 — Crab Nebula — Enceladus (moon) — Extrasolar planet — Galaxy — Globular cluster — Extraterrestrial life — H II region — Herbig-Haro object — Hubble Deep Field — Hubble Space Telescope — Kuiper belt — Open cluster— Milky Way — Moon — Outer space — Planetary nebula — Pluto — Roche limit — Solar eclipse — List of solar eclipses in the 21st century — Solar system — Sun — Star — Timeline of discovery of solar system planets and their natural satellites — Transit of Venus — Universe

Physics —

Alternating current — ATLAS experiment — CERN — Classical mechanics — Color — Electromagnetic radiation — Electron — Energy — Electricity — Electromagnetism — Fermi paradox — Force — Fuel — General relativity — Gravitation — Heat — Light — List of particles — Magnet — Mass-energy equivalence — Matter — Motion (physics) — Neutron — Nuclear fission — Optics — Quantum mechanics — Quark — Photoelectric effect — Proton — Sound — Spacecraft propulsion — Special relativity — Speed of light — Subatomic particle — Thermodynamics — Time — Vacuum — Wheel — Weight

Planet

Mercury — Venus — Earth — Mars — Jupiter — Saturn — Uranus — Neptune — Definition of planet — Planetary habitability — Timeline of discovery of solar system planets and their natural satellites