Descend 2,030 years into the past in an ancient tunnel built to support Jerusalem's most famous wall.

Historic fortifications form the boundary of Vatican City, but it’s not entirely surrounded by walls.

Breathtaking and huge 430 year old maps of Italy.

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

This historic covered bridge contains a series of macabre paintings that communicate one thing: everyone dies.

This memorial commemorating fallen Swiss Guards of the French Revolution has been called the saddest stone in the world.

A whimsical bridge adorned with decorative dragons.

The smaller of the three towers of San Marino is a former prison inaccessible from the ground level.

Portugal's National Pantheon has a history of curses, collapses and financial problems.

Elaborately carved to showcase the glorious wealth that the age of exploration brought to the Portuguese empire.

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

This statue of the great Argentinian car driver is located near a famous curve of the Monaco Grand Prix.

Every year, the town of Menton, France, turns lemons and oranges into giant sculptures depicting windmills, dragons, and more.

Two geological phenomena in one precarious locale: a towering stone window, and a deep blue void.

This church is named for one of the most dramatic tales in the early Christian church.

The floor of this spectacular Baroque sanctuary is covered in memento mori.

An abandoned set from the 1980 film "Popeye," claimed and repurposed as a theme park by creative locals.

A Bronze age settlement on the Greek island of Santorini might have been the inspiration for Plato's Atlantis.

A quirky bookstore hidden beneath a sea of whitewashed Greek villas.

This scale model of our solar system hid in plain sight for years before a physics team sought out all the planets.

The topiary maze at the Habsburg hunting lodge.

Built to give thanks for the passing of a plague epidemic, this cathedral is a one-of-a-kind architectural hybrid.

One of the two original gateways into the Kasbah, this gateway is a nesting site for storks.

The oldest monument in Marrakesh and the city's only surviving example of Almoravid architecture.