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

One of Mexico's youngest major cities still holds on to this structure representing its short modern history.

One of the oldest active carousels in the country—but it might be missed by all but the keenest-eyed boardwalk strollers.

The house that Frank Lloyd Wright "(shook) out of his sleeve at will" at the age of 86.

The massive, original Colgate Clock is mounted on a defunct factory building that was once a prison.

Marine fossils from the Devonian period are exposed at this park.

Once one of the most polluted caves in America, now an environmental success story and a museum dedicated to caves.

A poignant memorial to a young boy whose death spurred a dramatic increase in organ donations in Italy—dubbed the "Nicholas Effect."

The southernmost outpost of the Russian Empire in colonial America.

This whimsical seashell-shaped place of worship was designed to blend into its surroundings.

The mysterious round rocks of Schooner Gulch.

This Wyoming town is fascinated by a particular mythical creature.

The only natural lake in the world that drains into both the Atlantic and Pacific Oceans.

This rustic old building is said to be the most photographed barn in America.

This canyon is named for a unique geologic formation where the river vanishes underground near the mouth of the canyon and reappears farther down.

A devilishly named gorge that was a sign of salvation for many pioneers.

Named after an outlaw who used the basin as a hideout.

These tall, red sandstone pinnacles outside Moab are often forgotten amid their more famous neighbors.

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.

Few things look more out of place than the electric blue ponds in the reddish-brown desert of Utah.

This site is home to ancient petroglyphs and pictographs dating back to 6,000 B.C.

The unusual patterns in this rock formation result from two distinct modes of weathering.

A tunnel with windows, so you don't miss out on the impressive views.

Although it also features red, orange, and variegated cliffs of Navajo Sandstone, this state park is often overshadowed by its more famous neighbor.