This is one of the very few intact windmills built by the Knights of St. John in the island nation of Malta.

These temples are among the oldest free-standing stone buildings in the world.

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

People have been making salt here using traditional methods for centuries.

Burial grounds for more than 1,000 bodies deep under the modern town of Rabat.

The eyes and ears of this tower keep watch over Malta’s Grand Harbor.

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

Valletta’s outdoor theatre stands within the ruins of a 19th-century opera house.

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

The complex has been abandoned since the Croatian War of Independence, barring a stint as a set for 'Game of Thrones.'

A wunderkammer of gold and silver reliquaries and ancient saintly bones.

An ancient knight and a symbol of the city's freedom.

This home is decked out like a psychedelic explosion of colors and bowling balls.

The smallest post office in the United States is no bigger than a broom closet.

A building so large that it has its own weather.

Japanese gardens dedicated to the Japanese farmer that refused to throw in the trowel.

A failed, un-built suburb that has been going feral for decades.

This 25-foot tall clock tower commemorates the start of one of America's foremost shopping districts and the end of the historic Palm Beach Pier.

This railroad and oil tycoon's lavish estate now stands as a time capsule of the Gilded Age.

These craggy limestone outcrops offer a glimpse at a unique piece of Florida geology.

Before this area was filled with luxury homes, it was a movie star's 160-acre ranch and a gangster's hideout.

A massive line that stretches across the floor of Bologna’s largest church was created by a 17th-century scientist to measure the movements of the Sun.

Stuck in the arcade of Casa Isolani are three arrows of mysterious origins.

An extraordinary collection of 18th century anatomical waxworks.