Masada (Hebrew: metsada, "fortress") is an ancient fortification in the Southern District of Israel situated on top of an isolated rock plateau, akin to a mesa. It is located on the eastern edge of the Judaean Desert, overlooking the Dead Sea 20 km (12 mi) east of Arad.

Herod the Great built two palaces for himself on the mountain and fortified Masada between 37 and 31 BCE.

According to Josephus, the siege of Masada by Roman troops from 73 to 74 CE, at the end of the First Jewish–Roman War, ended in the mass suicide of the 960 Sicarii rebels who were hiding there.