A theme park that suffered massive flooding during Katrina was abandoned, and now proves irresistible to trespassing explorers.

A snapshot of the city's fascinating voodoo culture.

A museum and shop on Bourbon Street located in the former home of the second Voodoo Queen of New Orleans.

This eccentrically decorated palace is replete with grottoes, fountains, tunnels, and caves.

A modernist church in an ancient village.

This mountaintop observatory is home to one of the world's largest reflective telescopes.

This abandoned, turn-of-the-century astronomy hub is now the subject of more photographs than it ever took.

A five-square-mile slice of Spain on the Mediterranean coast of North Africa.

An impressive display of ships and artifacts from the ancient Mediterranean maritime trade.

A display of torture devices used in the Spanish Inquisition and other scourges of medieval Europe.

12th-century holy complex shares land with a natural park full of heavenly waterfalls and raptors.

The morbid items in this small and hidden museum are not for the weak stomached.

The oldest Roman lighthouse still in use.

This ancient Spanish castle sits high upon a hilltop.

A medieval village holds a very modern hotel.

Stunning Roman aqueduct used for 1900 years and still standing.

A completely underwater art museum sends a stark message about humans' impact on the environment.

This awesome Spanish castle is so fantastical it was actually used on Game of Thrones.

Giant eggs, walls of bread, and nightmare surreality mark the largest collection of works by Salvador Dalí.

Barcelona's historic 19th-century sewers, whose foundations were laid in medieval times, are open to the public for exploring.

A museum dedicated to the Spanish occult in a town that was terrorized by the Inquisition.

Three bridges and one giant canyon make up this fantastic Spanish settlement.

An enchanting monastery in the Spanish countryside appears lifted from a fantasy tale.

A gravity-defying "devil's bridge" that has a surprising architectural feature for its stability.