Electrical curiosity museum housed in an old transformer station.

A museum in the childhood house of a medical pioneer.

From Austrians to Nazis to Soviets, this historic Budapest fortress has a history as complex as the city itself.

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

Once the home of a hermetic monk, this cave now houses a small church.

This Hungarian castle was built out of cardboard and wood until it proved so popular that it got upgraded to stone.

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

The only surviving choragic monument is a trophy awarded in 334 BC for the winning dramatic chorus.

A grotesque collection of wax limbs depicting the symptoms of venereal disease.

The ruined doorway is a portal to the building's turbulent and torturous past.

This small 16th-century church in Athens is almost entirely surrounded by a modern building.

The ruins of an ancient Roman tomb hidden in the basement of a trendy clothing store.

The oldest cemetery of modern-day Athens blends the modern and ancient worlds.

The railway carts travelers to central Athens's highest peak, which offers stunning vistas of the city.

This ancient hydrological marvel is now the base of a modern outdoor cinema.

An ancient octagonal weather station named for the eight Greek gods of wind.

This mystical orb covered in strange symbols is thought to have been used in ancient Greek magical rituals.

Where commuters walk through remnants of an ancient Greek necropolis.

This ancient Greek place of assembly and marketplace is being revealed layer by layer below the modern Athens cityscape.

150 or so scrounged-up lamps, chandeliers, and lanterns light up this alley in central Athens.

A 2,000-year-old computer demonstrates remarkable engineering and astronomical precision.

Fantastic views and thousands of love locks.

An abandoned underground bathroom is now a space for public art.

Twisted buildings adorn the banks of the Rhine river.