Ruins of the Crusaders' headquarters.

A 1,500-year-old ghost settlement is slowly fading away.

Granite rocks that concentrate waves into powerful jets.

One of the best beaches in the entire world.

The history of sea-faring refuse and disaster is on cramped display in this Netherlands folk museum.

A curious collection dedicated to human and animal anatomy and pathology.

The history and future of cannabis.

Museum preserving torture methods from the past.

The Bauhaus-style former industrial complex is considered the world's most beautiful coal mine.

This "floating railway" is one of the world's oldest monorail systems.

Major tourist destination known for its bubbling mud-pools and hot thermal springs.

A Maori village obliterated by an 1886 volcanic eruption.

Tubing through a cave lit with glowworms is a magical underground experience.

A New Zealand communications tower stands as the tallest structure in the Southern Hemisphere.

Modern-day cave dwellers carve elaborate homes out of volcanic debris.

An underground city of salt.

A castle perched precariously over the Crimean Sea.

In the land of the Light Brigade stands a testament to the Cold War.

The largest catacomb system in the world.

A forgotten remnant of the Soviet Union, Transnistria is an unrecognized country hidden behind a heavily militarized border between Moldova and Ukraine.

The largest wine cellar in the world is a 150-mile network of underground caves near the capital of Moldova.

A mysterious castle built as a monument to lost love.

Flamboyant architecture from the turn of 20th century.

3,000 market stands in five former Zeppelin hangars.