The geological structure of Judea is highly favorable to the formation of caves; and the whole region abounds with subterranean caverns of various dimensions, often giving rise to small rivulets. These were used as dwellings, places of refuge, and tombs. It was in a cave that Lot resided after the destruction of Sodom, Genesis 19:30. Petra, in Idumea, was a city of caves, Numbers 24:21 Song of Solomon 2:14 Jeremiah 49:16 Obadiah 1:3. In the vicinity of Hebron, the poor still live in caves while pasturing their flocks. Natural cavities were sometimes enlarged, and artificial ones made for refuge and defense, Judges 6:2 1 Samuel 13:6 Isaiah 2:19 Jeremiah 41:9. The caves of Machpelah, of Adullam, of Engedi, of Carmel and of Arbela, still exist. See SEPULCHRE.