The first declared National Monument in the United States.

A small metropolis of Pueblo cave dwellings have been carved right into the hillside of this national monument.

Despite time, colonization, and the brutal New Mexican heat, these Pueblo ruins still stand.

These ruins of a pre-Columbian cliff village are among the most beautiful and well preserved in New Mexico.

A multi-storied adobe complex has been inhabited for more than a thousand years.

A museum dedicated to the alleged Roswell Incident.

The second-largest cave chamber in the world was discovered in 1898 by a 16-year-old and a friend known as "Pothead."

Explore the largest pure gypsum deposit in the world, and go dune sledding while you're at it.

This spectacular track has run continuously since 1882.

The ancient dwellings of the Puebloans, located in the cliffs of majestic mesas.

See massive fossils that are over 200 million years old in northeastern Arizona.

Colorful sand dunes create a unique attraction in this part of Utah's red-rock country.

The fifth-longest natural arch in the world, and the longest outside China.

Giant, natural amphitheaters made of delicate geological formations called "hoodoos."

A desert ghost town—occupied for only 12 years—was once home to more than 500 silver mines.

Quite simply the largest tree in the world (by volume).

A monument to peace, built by one man over the course of 25 years.

A massive observation tower that features gorgeous views and unique architecture.

Unconventional site where the tracks of Zurich tramcars intersect.

A communal oasis on Lake Zurich.

An 11th-century fortress home to one of the most influential royal houses in medieval Europe.

The oldest surviving wooden bridge over Rhine lets travelers cross easily from Switzerland to Liechtensten.

The bears of Bern have been a city highlight for over 500 years.

One of a series of no-purpose kinetic artworks by Swiss sculptor Jean Tinguely.