An 18th-century townhouse that once hosted guests of the president.

Behind these delicious arepas lies a true New York success story.

This striking arch, one of the first architectural elements constructed in Prospect Park, was recently restored to its original glory.

This hidden oasis features a stunning view of the Hudson River and the Palisades from a castle-like museum.

Historical figures from New York City's Catholic community reside in Midtown.

A clock set into the concrete outside a Manhattan jeweler has been telling time underfoot for over a century.

This Philly cemetery is the eternal home of many famous area residents, including Rocky Balboa's wife.

A morbid secret lies hidden within the beautiful walls of the Boston Athenaeum.

Macabre headstones carved with winged skulls, dancing skeletons, and pithy reminders of impending death.

This Boston medical museum features the skull of the famous medical case of Phineas Gage.

The "Key of Keys" for Washington, D.C. and the apocryphal landing place for the military campaign that started George Washington's career is now at the bottom of a well.

People escaping slavery may have hidden inside a corpse vault.

At this beautifully preserved Pre-Hispanic site, you can see ancient petroglyphs with depictions of llamas and alpacas.

Hand-made memorials and a wish-granting murderer lie within this seaside pauper's cemetery.

A massive display of meteorites all found in the Atacama Desert.

One of the largest ancient geoglyphs in the world is a tall desert god used for predicting the weather.

This Japanese-inspired labyrinth of hot springs is hidden in a Chilean forest.

Depending on who you ask, this controversial treehouse is either a charmingly creative child's playhouse or an illegal encroachment on public land.

The privately owned cemetery that holds room for Washington's finest when they step down from life.

A hidden gem full of oddities, curiosities and macabre antiques.

A restaurant and observation deck built in a unique broadcasting antenna.

Gardens representing parts of Asia, Europe, and the Mid East are tucked away among the Soviet-style buildings in East Berlin.

One of the oldest cemeteries in Germany was originally used for victims of a cholera epidemic.

A homage to the King at the hotel where he revived his career.