Caves are very often found in limestone due to its high solubility, which virtually guaranteed that many would be found in the land of Israel.
Limestone is very common there.
In The Past Caves were often found in the Bible Places of Bible History . After this, Abraham buried Sarah his wife in the cave of the field of Machpelah east of Mamre, that is, Hebron , in the land of Canaan. Isaac and Ishmael his sons buried him in the cave of Machpelah, in the field of Ephron the son of Zohar the Hittite, east of Mamre, the field which Abraham purchased from the Hittites. There Abraham was buried, with Sarah his wife. When Jacob finished charging his sons, he drew up his feet into the bed, and breathed his last, and was gathered to his people.