National Monument

The only undammed section of the Columbia River in the United States has been preserved, ironically, by its proximity to the Hanford Nuclear Reservation.

An ordinary rancher stumbled upon one of the world’s largest collections of Pliocene horse fossils.

A Soviet-style monument, built after transferring the remains of heroes from their graves.

A large, remote national monument highlights the typical geologic structure seen in Nevada.

This site honors the end of a 100-year boundary dispute between the United States and Mexico—all started by a river's shifting course.

This rock formation above the Wabash River is part of an ancient coral reef.

The remains of Abó, Gran Quivera, and Qurai are monuments to the long, complicated history of the Indigenous people of the Southwest.

An aptly-named street near the birthplace of the modern LGBT rights movement.

This arid landscape was once a lush wetland. Today, it's a paleontological site filled with fossilized mammoths, sabertooth cats, and more.

For over a century, it has been a tradition to raise a flag at the top of this 450-foot sandstone pillar on the 4th of July.

Red sandstone structures dominate this landscape, which has been inhabited for some 5,000 years.

The hallowed remains of a 900-year old Ancestral Pueblo great house.

Inside this striking glass building, visitors can see thousands of dinosaur fossils in the positions that nature deposited them more than 150 million years ago.

Atop an active stratovolcano, two lakes separated by a narrow strip of land.

Thousands of pieces of art have been carved into the rock at the site of an ancient volcanic eruption.

A strenuous, unofficial trail leads to spectacular views in one of America's most remote national monuments.