Shoshone Ice Caves are Idaho's best-known caves. They are rated by Sunset Magazine as one of the Northwest's main points of interest. In country that easily gets above 100 degrees in the summer, the caves maintain a constant interior temperature of 18 to 33 degrees. Bring your coat and sturdy shoes.

Tours take visitors through a 1,000-foot-long cavern that is some forty feet high and varies in width from eight to thirty feet. At the far end of the cave is a wall of ice of unknown depth, despite repeated attempts to determine it.

To understand these caves, you must know that as molten lava poured over the land now known as the Snake River Plain, bubbles, tubes, and fissures formed on a grand scale. Shoshone Ice Caves are actually a series of craters lying against a volcanic rampart that cooled earlier than the ice caves did.

T-Maze Caves, a complex series of lava tubes, are part of the Bennett Hills Recreation Management Area, which is administered by the Bureau of Land Management. Fourteen caves and a "blister" form what many experts contend is the best example of such formations in Idaho.