Here's an interesting story about a monk in Georgia (that's eastern Europe, not the US) who has been living at the top of a natural pillar since 1991. Maxime the monk says, "It is up here in the silence that you can feel God's presence." As a young man, the monk "drank, sold drugs, everything," but he decided he needed a change, and became a monk-- and a pretty extreme one, at that.
Stylites (pillar saints) were once common in the area, but the practice was abandoned a long time ago. Maxime has a small cottage at the top (though he originally slept in a fridge), as "it's more about isolation than suffering." His followers send up food and supplies via a winch. With age, his ability to climb the 131-foot ladder is fading, and when he can no longer climb the ladder, he intends to stay at the top till he dies.
People do some pretty extreme things in the name of religion, but looking at the photos, it doesn't look all that crazy. It's a beautiful view, and there's something to be said for isolation. I do suspect, though, that remaining atop a pillar for twenty years could cause anyone to hear the voice of God, just out of sheer boredom and loneliness.