Hole-in-the-Rock
Phoenix, Arizona
Before there was the Skywalk or the Wigwam Motel or even Tombstone as Arizona tourist attractions, there was this thing: an exposed desert butte of arkosic conglomerate sandstone with a big hole eroded through it. People like to climb out of the sagebrush, up the butte, and stand in the hole.
Hole-in-the-Rock is now part of Papago Park, and may have been the inspiration for Albert Christiansen's Hole N' The Rock attraction in Utah -- or does that state have its own butte with a hole?