Home to Hollywood history and a very special salt crystal.

This hidden 13th-century tavern room has a few Shakespearean connections.

The secret room where early Bolsheviks cranked out propaganda fliers on a smuggled printing press.

This lab's maddening silence is good for business but bad for sanity.

The hidden lair of an alchemist rediscovered in a 2002 flood.

A room in New York City that contains 250 cubic yards of dirt.

In Lago Superiore, the largest expanse of lotus flowers outside of Asia is hard to miss.

A geothermal energy project gone wrong is fracturing the city's picturesque architecture.

A Manhattan tombstone honors a popular 19th-century heroine, now long forgotten.

At this leafy estate, one man’s passion for trees grew into Arbor Day.

The eccentric mansion of one of the most popular horror authors of modern times.

This headstone-like marker inscribed with three words has been an utter mystery for over a century.

A three-centuries-old crypt in the foothills of an old plantation.

Some 2,000 carvings show this rare desert spring has been an oasis for travelers for over a thousand years.

Here lies Lilly E. Gray, an alleged "victim of the beast," but the reason long remained a mystery.

This small shop walked so America could run on Dunkin'.

The first "Hut" was actually a small brick building.

On the outskirts of a desert trading village high on the Andean plain, steel giants have been destroyed by salt winds.

This unusual subway stop was originally a real estate office.

This abandoned subway station beneath the Waldorf-Astoria hotel is allegedly used to secretly transport presidents.

World-famous, Pink's still manages to keep its prized cult fetish status.

A hotel and restaurant serving as the mecca of kitsch.

The cheese slicer may be a Norwegian invention, but the biggest ones in the world are found in Sweden.

This residence straddles a border between Belgium and the Netherlands.