No one knows who built this strange cave of worship or exactly why.

The possible imprisonment of Vlad the Impaler here earned the medieval castle its nickname, "Dracula's Castle."

The European towns of Brașov and Râșnov each have proud signs reminiscent of the Hollywood sign.

This snug medieval lane is one of the narrowest streets in the world.

A fire once nearly devoured this gorgeous 14th-century Gothic cathedral.

This underground oasis is one of North America’s most fascinating prehistoric places—and you can scuba dive in it.

An abandoned facility that has become a place of ritualistic satanic worship, or so rumor has it.

This elaborately decorated, fairytale-like Romanian royal palace is one of the most striking castles in Europe.

One of the most controversial statues in Romania is an emperor with no clothes.

This memorial to the victims of the Romanian Revolution of 1989 is often compared to a potato on a skewer.

The only Roman honorific column in Istanbul.

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.

A fountain standing as a testament to a doomed alliance.

An underground world of gorgeous, palatial metro stations designed as a nuclear shelter complex.

Prowl through this sprawling bazaar under a massive Soviet-era dome for delicious eats.

The heartbeat of modern Uzbekistan’s thriving market culture.

This magnificent blue mosque in Afghanistan is surrounded by thousands of white doves.

Ancient barriers wrap around what was once an important stop along the Silk Road.

The first version of this stalwart construction appeared around 3,000 years ago.

Light still pours into the ruins of this ancient Islamic observatory.

Home to what was once considered the largest gate in central Asia.

An 18-meter-long sarcophagus of a constantly growing dead prophet.

The Avenue of Mausolea is a series of grand palatial tombs.