This Arizona observatory is famous for investigations into Martian life, and as the place humans first spotted Pluto.

This 4,000-foot-diameter hole is touted as "the most well known, best preserved meteorite crater on Earth."

The most loyal of little dogs, or a Victorian era publicity stunt?

Remnants of the 16th-century defensive wall still stand unassumingly within Edinburgh.

Touching this 18th-century Scottish philosopher’s toe allegedly conjures good fortune.

This otherwise ordinary close on the Royal Mile constituted the end of the world for Edinburgh’s poorest residents.

A 18th century graveyard and its astonishing cortege of macabre iconography.

Preserved baths in a Victorian-era spa town frequented by the most famous people of its day.

This historic observatory contains the world's oldest refracting lens telescope.

This controversial museum includes such detested exhibits as a chocolate suicide bomber and fecal-smelling digestion machine.

This garden houses the remains of the ancient Greek port of Marseille.

This ancient Roman bridge and aqueduct still stands as a wonder of classical construction.

This ancient theater was once the home of fierce gladiatorial battles.

The world's most famous cheese caves.

This plaza is home to a number of works, including Montpellier‘s own Arc de Triomphe.

This Bordeaux parking garage has 712 indoor spaces, and one outdoor.

The world's largest reflecting pool is just two centimeters deep.

This huge abandoned fortress hidden inside a mountain holds a world of subterranean secrets.

The largest madrasa in Morocco once housed more than 900 students within its exquisite walls.

Fortune tellers, snake charmers, poets, and storytellers all gather on this historic square in Morocco.

One of the world's most complex timepieces.

A beautiful and classically designed villa, with an hourly infestation of monsters.

An ancient ossuary in Rouen.

Two small chapels housed inside an ancient tree.