The most popular hike, the one that goes into the chasm itself, is also the most treacherous, yet it was easy enough for Amelia, our 7-year-old daughter. (I had to lend a hand so she could steady herself only a few times when climbing up or down some of the larger rocks.) The hike descends immediately toward the chasm floor, providing gorgeous views of the 70-foot-high granite walls, which have trees improbably growing out of them. Hikers must be careful on the trail. One wrong move can easily result in an ankle sprain, skull fracture, or worse. Points of interest such as caves are marked along the way; perhaps the most interesting of these is Fat Man's Misery, a narrow crevice between boulders that most people can pass through only if they turn sideways.

Geological wonder aside, Purgatory Chasm is also a great place for a picnic. After a couple of shorter (and much easier) hikes, we ate our lunch atop the giant slab of granite that greets visitors at the park's entrance. (Though it appears to be nearly vertical from the road, the rock is inclined just enough for kids to climb up and down; Aidan and Liam obliged.) We finished lunch just down the road at West End Creamery, which sells 50 varieties of homemade ice cream, including the best coconut almond fudge I've ever tasted. How convenient.