Valles Caldera National Preserve, National preserve and Dark Sky Park in the Jemez Mountains, New Mexico, United States.

Valles Caldera National Preserve protects 95,000 acres (380 km2) of the Jemez Mountains in northern New Mexico, centred on a 13.7-mile-wide (22.0 km) volcanic caldera. Grass valleys called valles open across the caldera floor; Valle Grande is the largest and the only one reached by paved road. Redondo Peak, an 11,254-foot (3,430 m) resurgent lava dome, rises entirely inside the caldera, surrounded by moat-like flows of solidified rhyolite.

The caldera formed about one million years ago through a major volcanic eruption that shaped the entire landscape. The land transitioned from private ownership to a national preserve in 2000, establishing it as a protected area for conservation.

Obsidian from the caldera was knapped into tools and weapons and traded by tribes across much of the Southwest. When the federal government bought the Baca Ranch in 2000, 5,000 acres went to the Santa Clara Pueblo, including the headwaters of Santa Clara Creek, which is sacred to the pueblo.

Visitors should expect variable weather and cooler temperatures at higher elevations, so bringing layered clothing is essential. Evening stargazing programs benefit from bringing a camp chair and red-mode lighting to preserve night vision while exploring the dark skies.

The caldera's obsidian was knapped into tools and traded by tribes across much of the Southwest, and spear points dating to 11,000 years ago have been found here. Visitors can also look for Redondo Peak, an 11,254-foot resurgent lava dome standing entirely inside the caldera ring.