This staircase in a lush tropical grotto was built by enslaved laborers and renamed to honor Queen Victoria's role in ending slavery in the British Empire.

A massive underwater sinkhole made famous by Jacques Cousteau.

This incredibly diverse research station is one of the largest tropical botanical gardens in the world.

This restored opera house is named after a soprano known for tragic romance, exile, and a truly uncomfortable wedding.

A wooden sculpture sits rather out of place in this Mexican beach town.

The ruins of this abandoned fort now stand as a picturesque reminder of America's march West.

"I did this all while you were watching TV."

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

These aggressively sustainable art homes look like something out of 1970's science fiction.

The oldest original lighthouse in Alaska that was born out of a tragic shipwreck.

A classic gold rush hotel can be expected to pick up some ghosts along the way, and the Golden North is no exception.

A monument commemorating the role of Alaska's native Tlingit guides in the Klondike Gold Rush.

At 135 years old and counting, this historic print shop is heaven for poster nerds and music buffs.

This church houses the “incorrupt” body of its founding Bishop.

A giant open-air sculpture made of over 200 full-sized boats.

These banned cigarette vending machines now sell little pieces of pocket-sized art.

An exotic wildlife habitat right off The Strip.

This 4,000-foot-diameter hole is touted as "the most well known, best preserved meteorite crater on Earth."

A house carved into a rock in the 1940s.

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

This raised bulls-eye visible from space was the subject of an intense geologic controversy.

One of the world’s largest collections of petroglyphs records 2,000 years of human activity.

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

This memorial pays homage to Pueblo's four Medal of Honor recipients.