Hidden beneath the famous St. Peter's Basilica is a veritable city of the dead that may hold the remains of St. Peter himself.

Breathtaking and huge 430 year old maps of Italy.

If you want to talk to the Pope you will have to stare down this surreal vision of Jesus rising from a nuclear hell.

This futuristic German television spire is actually the world's largest digital clock.

Twisted buildings adorn the banks of the Rhine river.

Drink among marionettes at this pub inside a historic puppet theater.

When you're a great Russian Tsar, even your vomit gets a statue.

Meet the bronze beloved pet to a family of famous peeing statues.

Climb inside an iron crystal magnified 165 billion times its normal size.

Unconventional site where the tracks of Zurich tramcars intersect.

This charming fountain honors Felix Salten, the creator of the iconic storybook deer.

A king's pet, a pope's gift, an artist's inspiration, and a tragic shipwreck.

The ruins of the largest gladiatorial school in Rome are largely hidden under modern streets.

Ancient ruins hidden underneath a modern luxury hotel.

2300-year-old Roman road connecting the empire.

The wooden telephone box hidden away in London's Piccadilly was the original prototype of the iconic kiosk.

These official units of measurement—including chains and perches—lie hidden beneath tourists' feet in a popular London hub.

Pop culture has helped to keep this iconic British building from being destroyed.

London's last remaining public soapbox site has seen speeches from Karl Marx, Vladmir Lenin, and George Orwell.

Eighty million natural history specimens call this gargantuan museum home.

One of Amsterdam's narrowest houses is located right across the canal from its widest.

A public urinal so pretty, it was declared a national monument.

This museum housed in a former brothel explores the past and present of sex work in Amsterdam.

The history and future of cannabis.