This futuristic German spa allows visitors to float in a pool of salt water while zoning out to underwater techno.

A walk down memory lane in the heart of one of San Francisco's most notorious neighborhoods.

This fairy-tale castle would make Dracula (who is said to have been imprisoned there) jealous.

Gilded heaven for philatelists and architecture freaks, still in full working order despite sitting atop tremulous ground.

Since the 1700s, this old barrel has acted as a post box that relies on the kindness of travelers.

"Portugal's Stonehenge" is made up of nut-like stones aligned with the heavens.

The oldest giants in Catalonia are now displayed in a 14th-century Gothic church.

Austria's very first and only nuclear power station was completed but never used.

As can be expected from a centuries old church built in a canal city, the undercroft of this house of worship is beautifully flooded.

Mosaics, storks, and brothels—this ancient city has it all.

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

Construction of Barcelona's iconic (but controversial) church is expected to be completed in 2026—a century after the death of its architect.

An abandoned saucer-shaped monument in the Bulgarian mountains.

The birthplace of the very first human resident born in Antarctica.

A trailblazing sovereign nation tucked in the American state of Wisconsin.

Eurasia's most difficult place to hang out, and farthest point from sea access.

This 19th century brick building in Brooklyn stands out like the anachronistic landmark that it is.

This Venice bookstore has resigned itself to constant flooding by keeping its books in bathtubs and boats.

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

A surreal museum of extraordinary industrial objects.

The legendary cliffside castle of three-time Voivode of Wallachia, Vlad the Impaler.

A park in Mexico offers all the experiences of an illegal border crossing except for one: the border.

A small island less than half a mile from Venice is a forbidden island with a dark and twisted past.

This classic restaurant features a gorgeous mirror-clad room.