Barrier
Great Barrier Reef
Barrier methods
Israeli West Bank barrier
Blood–brain barrier
Iran–Pakistan barrier
Barriers to entry
Thames Barrier
Belize Barrier Reef
Barrier island
The Great Barrier Reef: Biology, Environment and Management
Sound barrier
Fox Point Hurricane Barrier
Barrier of the Unknown
Bangladesh–India border
Line of Control
August Weismann
Golan Heights
Durand Line