A former sanitarium where soldiers were sent to recover in the healing waters of hot springs.

A bronze monument to his majesty, King Gino.

An aptly-named street near the birthplace of the modern LGBT rights movement.

Packed with geological formations, an ancient river, and taxidermied seals, this overlooked coastal cave system is worth a spelunk.

One of the oldest art supply stores in the United States.

An ancient Greek monument and a Byzantine church coexist inside this cave.

The drawbridge used in the filming of the movie 'Annie' has been in the open position as it was in the movie for decades.

This abandoned church was the site of one of the biggest art heists of the past decades.

Underground attraction offering tours of the foundational ruins of a church nave that collapsed in 1674.

A tribute shrine where the Space Invasion street art movement started.

A museum dedicated to the history of sugar cultivation on Réunion island.

This once rural mansion now sits in the heart of the city.

The largest collection of historical roller skates in the world.

When an ancient supervolcano erupted, some of Nebraska's prehistoric animals were forever preserved in ash.

The two-cell building in Nebraska was briefly owned by a teenage boy and then a Hollywood dummy.

The home for all things Kool-Aid offers everything except a chance to actually enjoy the drink.

Underneath downtown Lincoln resides a network of caves that was also the city's first brewery.

A brick-paved former section of the historic coast-to-coast highway.

Roaming bison and a spectacular view at the highest point in Nebraska.

Other-worldly rock formations and ancient fossils abound in this unique stretch of Nebraska badlands.

A 14th century bridge built as a fortress, where the devil lurks on one of its towers.

Hundreds of hidden passageways weave through the old quarters of Lyon.

A cave dwelling that was started by the Celts, expanded by monks, and finished by knights.

This off-limits room in the National Library of France is home to a system of pneumatic tubes, once used to bring books to readers.