A centuries old castle atop a dormant volcano houses museums devoted to both women and witches.

Breathtaking and huge 430 year old maps of Italy.

One of the deepest blue holes in the world.

This solitary monastery may hold the remains of Vlad the Impaler (but probably not).

The lush coastal city of Astoria is riddled with forgotten secret sidewalks.

One of Japan's most famous sights, the bridge was originally built in 1673.

An ancient stone fortress considered by many to be the eighth wonder of the world.

This domed temple was built in a hidden cave mouth as a refuge for sinners seeking absolution.

The only "Egyptian" pyramid in Europe and the legendary tomb of Remus.

A monument in Washington D.C. marks the spot from which all other roads were supposed to stem.

A living archive of urban activism and space reclaimed.

The longest living non-clonal organisms on Earth.

Explore the complex ecology of this multifaceted nature preserve by riverboat.

Come for the speed, leave in love with the desert.

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

A remarkable geological formation resembling a forest made of stone.

This floating garden in the sky is straight out of a fairy tale, but the real thing is nothing short of magical.

A Belgian self-built tower inspired by the Bible and ancient civilizations.

The first island in the world designated a light-pollution-free astronomical observation point.

Once an opulent Art Nouveau hotspot, the Constanța Casino is one of Romania's most beautiful abandoned buildings.

The hottest place on the planet.

On the outskirts of a desert trading village high on the Andean plain, steel giants have been destroyed by salt winds.

The vast chamber inside this abandoned cooling tower looks like something out of a sci-fi dystopia.

Who needs fancy modern water slides when this giant North Carolina rock works just as well?