Thousands of coffin-like pillars make up this controversial Holocaust memorial.

The most visited, and possibly most controversial, museum in Germany.

The slender brass strip in Prague's Old Town Square was used to tell time from 1652 to 1918.

Macabre astrological automaton clock dating to the late 1400s.

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

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

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

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

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

The ancient latrines of the Greeks, in all their public glory.

The alleged house of the Virgin Mary is tucked away in a park and nature preserve on Mt. Koressos in Turkey and is holy to both Catholics and Muslims alike.

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

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

The deepest underground city in Turkey was designed to protect 20,000 people behind massive stone doors.

A deadly ancient portal to the underworld.

These tombs were built into the side of a mountain so that ancient angels could reach the dead.

A marvel of Byzantine engineering under the streets of Istanbul.

Roman ruins top white travertine terraces formed by ancient hot springs.

In this historic region, homes and churches are carved into ancient volcanic rock formations.

Abandoned bull fighting ring, slowly falling apart in Uruguay.

The design of the Palacio Salvo has been described as "a lighthouse on top of a building."

An elaborate shrine dedicated to the four corners of the world unfortunately misses its mark.

A turquoise lake within a volcanic crater.

Dedicated to the first German Chancellor, Otto von Bismarck, this aging edifice is the only one of its kind in the Americas.