This Ottoman-era church is hidden amid a busy tourist area.

A man's head is enshrined beneath a statue near the first building constructed for the modern Olympic Games.

A Byzantine church containing the holy remnants of three saints sits atop the site of an ancient temple.

Where commuters walk through remnants of an ancient Greek necropolis.

This ancient structure appears Roman, but was constructed during the 16th century and was utilized until 1911.

UNESCO-protected ancient burial ground.

The remarkably well-preserved final resting place of a powerful ancient Thracian king.

A magnificent, glittering building tucked into a tiny Bulgarian mountain town.

A mountain pass in Bulgaria's Balkan Mountains was the site of four historic battles.

This massive concrete sculpture is said to be the heaviest communist monument on Earth.

Rebuilt several decades ago, its striking murals prevent it from being reconsecrated as a church.

A decaying, yet still functioning, work of communist architecture.

An homage to the medieval rulers of Bulgaria.

The site of many battles and tragedies, including the 40 maidens who leapt into the sea.

Mysterious standing stone formations looks like a petrified forest.

Rock carving created 1,300 years ago 75 feet off the ground.

A stunning waterfall in the mountains of Romania.

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

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

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

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

The most impressive example of contemporary Romanian architecture in wood

The last active narrow-gauge forest railway in Europe.

The massive white mound and accompanying water terraces are a striking geological oddity.