This museum sits on the site of a decommissioned military communications base.

A unique collection of diving equipment spanning antiquity to the present day.

Few of the many visitors to this resort town know of its hidden Maya ruins.

The southernmost outpost of the Russian Empire in colonial America.

This alley off Edinburgh's Royal Mile contains remnants of the city's seedier history.

At the right time of day, sunlight floods through the roof of this cave and illuminates the small pavilion hidden within.

In this truly magical place, rent hasn't been raised since the year 1520.

This Scottish castle has witnessed clan rivalries, Jacobite uprisings, whisky smuggling, and more.

The world's tallest circular building is loaded with symbolism, but many just see a big donut.

Climbing this abandoned railway leads to breathtaking vistas of O‘ahu.

This spectacular track has run continuously since 1882.

This riverside restaurant has been serving customers since 1146.

A mysterious air force base built to resemble a Long Island fishing village.

The ruins of an ancient pyramid built by the mysterious Chupícuaro civilization.

These former Nazi anti-aircraft towers offer a singular view of the north of Berlin in the summer, and a sanctuary for bats in winter.

This Old West prison built into the side of a cliff was said to be inescapable.

Concrete crosses scattered across the Arizona scrubland which were used to align spy satellites.

A beautiful ruin of a 14th-century Plantagenet castle built by a medieval mercenary.

Despite its grandiose name, this enigmatic first-century void under the town is no cave, and it's possibly not a palace either.

Watch the seas clash at the place where according to Maori tradition, the spirits depart for their journey to the afterlife.

America's only nuclear missile silo open to the public.

The world's largest military aircraft cemetery.

You haven’t properly toured a winery until you’ve slept in an actual wine barrel.

This isolated island is often capped by its own fluffy cloud.