This Costa Rican chapel is the most metal church in the world, literally.

This bleach-white graveyard overlooking the ocean is accessed through a tunnel.

The crumbling remnants of this 19th-century quarantine hospital hint at the touristy island's darker past.

This small fort played a huge role defending Puerto Rico’s capital city.

An American city stranded at the tip of a Canadian peninsula where strict adherence to the "49th parallel rule" became problematic.

The largest self-built castle in the U.S., six decades in the making.

An immersive environment that is part haunted house, part choose-your-own-adventure, and part jungle gym.

This black shoreline is made up of exploded lava particles.

A sharp bend in a dramatic river canyon cut through red rocks.

A scenic natural bridge with a creek running underneath.

Locally known as the "Onion” and the "Egg Beater,” Casper’s most recognizable buildings are beloved local landmarks to many, and eyesores to others.

This historic Union Pacific Railroad depot is a stunning symbol of American post-Civil War progress.

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

The same security that protects our nukes accidentally protected a gentle herd of antelope.

The world's largest mineral hot springs is home to a herd of bison, a free public bath house, beautiful mineral formations, and a terrifying swinging bridge.

At the time of its completion, it was the tallest dam in the world.

The high point on the 16th president's eponymous roadway is marked by a massive version of his head.

Population: 1.

This Wyoming town is fascinated by a particular mythical creature.

A monument to the egos of two railroad magnates that fell into decline along with their careers.

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

Miraculous tree that seems to sprout out of solid rock.

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

One of the smallest towns in the United States.