Serra de Montejunto Protected Landscape is a protected landscape in the Montejunto-Estrela mountain range, spanning the municipalities of Alenquer and Cadaval in Lisbon District, Portugal. It is the highest natural viewpoint of Estremadura, rising to 666 metres (2,185 ft) of altitude.[2] The area is part of the Estremenho Limestone Massif. Geologically is 15 kilometres (9.3 mi) long and 7 kilometres (4.3 mi) wide, and is rich in caves, sewage ponds and prehistoric fossils.