Swimming in a pool surrounded by steep, 15-foot basalt cliffs is a once-in-a-lifetime experience to be had in Israel’s Yehudiya Forest Nature Reserve. Most of the columns that contain the 65-by-100-foot Hexagon Pool—a scenic swimming hole formed by the Meshushim Stream rushing grandly over the formations—are greater than a foot in diameter. This is the most spectacular of many basalt formations within the reserve, all caused by activity in the Golan Heights volcanic field.