This curious, round temple is the oldest still-standing marble building in Rome.

Before it was buried by volcanic ash, this fast-food restaurant fed the hungry hordes of ancient Rome.

Erotic art covers the walls of the largest ancient pleasure palace.

Medicinal spa created from the mineral-rich runoff of a geothermal power plant

The water-powered carriages are long gone, but for over a century this funicular railway has been the fastest route to the highest point in Paris.

This bridge was constructed from the rubble of the infamous Bastille.

This statue was given to France by the United States to commemorate the centennial of the French Revolution.

This demon atop the Notre-Dame de Paris looks utterly bored.

This fairy tale forest hides scenes from some of the more obscure and bizarre Western nursery stories.

Take a stroll through the hellish grotesques of Hieronymus Bosch in this elaborate Netherlands church.

A poignant memorial that traces two hundred years of German history.

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

The ruins of an ancient Zoroastrian Tower of Silence believed to be the earliest example of the traditional funerary practice.

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

The Catedral Basílica de Salvador is special for its stunning Baroque interior and the historic sepulchre of Mem de Sá, connecting the church to Salvador’s colonial past.

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

Once a luxurious flagship of the Soviet Union, this Brutalist structure remains a landmark of Tashkent’s communist past.

Where Stoddart and Connolly suffered in the infamous Bug Pit.

This "tower of death" has acted as an observatory, a religious hub, and an executioner's lair.

Right beyond the Uzbekistan-Tajikistan border lies the oldest human settlement in Central Asia.

Controversially restored in the 1970s, this giant 15th-century mosque is shrouded in legend.

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

Baroque celebration of the end of the Great Plague of Vienna.

The site of Austria's biggest concentration camp now honors its victims.