Boulder Caves in New Hampshire’s Lost River Reservation are rare talus caves formed by a shrinking glacier leaving behind huge boulders. These boulders form several caves, both in the riverbed and beneath. Some of the New Hampshire caves along the trail are big enough to stand erect inside, though others are very narrow.

The Lost River Reservation is located at Kinsman Notch, a pass between Mt. Moosilauke and Mt. Kinsman, close to North Woodstock in the White Mountains. The brook flows through the narrow, steep-walled Lost River Gorge. A series of wooden walkways, bridges and ladders make the gorge area accessible. The gorge ends at the Rotunda with a Covered Bridge.

Caves along the path include Cave of Odin, Devil's Kitchen, the Cave of Silence, Parallel Rocks, Center of the Earth, the Dungeon, Lemon Squeezer, Bear Crawl, Judgement Hall of Pluto and Shadow Cave, the biggest cave of them all.