These remote Florida islands have a history of sea turtles and sunken treasures, and one of the world's largest coastal brick fortresses.

"We Seceded Where Others Failed."

An icon among Florida's pre-Disney tourist attractions.

The unique collection includes bronze cast handprints of some of America's most famous astronauts.

St. Augustine's record-setting narrow street was designed to protect against pirates.

The walls of America's oldest masonry fort famously "swallowed" cannonballs.

A building so large that it has its own weather.

After the attack on Pearl Harbor, rocks and fossils from every U.S. state were collected into a pyramid of national unity.

Electrical pylon in the shape of Disney's beloved mouse.

This highest peak in New Mexico is named after an explorer who had a habit of lending his monicker to peaks.

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.

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

The final resting place of the most famous outlaw in the Old West.

Walk through the sets of old western films at this small museum in Utah.

Erosion and various mineral deposits give this striking canyon its distinct color and soft appearance.

This ancient cave is home to a museum, bar, and is filled with fluorescent minerals.

Hundreds of drawings left by the land's previous inhabitants remain mysterious.

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

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

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

Giant pinnacles in the sun-scorched lands of Southern Utah have been nicknamed "white ghosts."

This rugged area of red rocks and arches is often considered one of the most beautiful places on Earth.