 According to the Bible, the prophet Elijah travels to Mount Sinai and once he gets there, he goes into a cave and that's where he talks to God. The real Mount Sinai must therefore have a cave that is accessible, safe, and suitable for sleeping. This cave above the altar is about 15 feet high, 20 feet long, and 20 feet deep. If this is the real Mount Sinai, then this is almost certainly the cave of Elijah.