A 16th century chapel decorated with bones, skulls, and entire bodies hanging from the wall.

Hidden beneath a beautiful overlook you’ll find the history of the city depicted in comic strip format next to a pay toilet.

This Industrial Age architectural and engineering gem helps visitors and residents alike traverse Lisbon, “The City of Seven Hills.”

The world's oldest bookshop still in operation.

Legacy of the earthquake that nearly wiped Lisbon off the face of the Earth.

Climb a set of vertiginous stone steps to the top of this impressive ancient edifice.

This former Imperial summer home was the venue for a royal slap that once echoed 'round the world.

A sixth-century Byzantine cistern hidden below a modern carpet store.

Ancient serpentine sacrifice holder that has stood the test of time.

A fountain standing as a testament to a doomed alliance.

Legend says if you stick your thumb in the hole and it gets wet your wish will be granted.

1513 Turkish world map, full of European state secrets and snarky commentary.

This remarkably well-preserved Egyptian plinth is pretty well traveled for a giant piece of stone.

A small etching on the white marble parapet was written in runic script by a Viking mercenary.

The ornate miniature mansions were built for Istanbul's feathered residents.

Five sultans and their families rest in eternal splendor, teeming with overlooked beauty and drama.

A marvel of Byzantine engineering under the streets of Istanbul.

A statue in Budapest's Liberty Square honors the former U.S. president's efforts to end the Cold War.

Legions of Roman soldiers bathed in this ancient spa complex under a Budapest transit station.

A museum dedicated to a secret military hospital hidden beneath a castle in Budapest.

A Trabant car, a kangaroo statue, and a plethora of plants take over this abandoned-factory-turned-bar.

Built in 1870 at the bridge that connected Buda and Pest, this spectacular incline railway was almost lost forever during World War II.

A trail of iron footwear stands as a monument to the thousands executed along this riverbank during WWII.

A series of caves under Castle Hill that once held the prisoner Vlad Tepes, better known as Count Dracula.