The land is full of geologic eye candy, such as otherworldly spires, mushroom-shaped hoodoos, and prehistoric fossils.

A house carved into a rock in the 1940s.

The giant stump of the once towering cottonwood where Ute people held tribal meetings.

One of the American Southwest's most extensive collections of Navajo rock art.

A well-preserved Ancestral Puebloan ruin tucked beneath a desert cliff.

Colorado's only true geyser is hidden within the San Juan National Forest.

This spectacular track has run continuously since 1882.

The marker offers a rare chance to be in four U.S. states at once, though there's some controversy over its geographic accuracy.

A clock designed to run with perfect accuracy for 10,000 years.