A century-old shot ball factory tower is open to the public once a year.

This conical hill was built as a testing ground for an engineer known as the Glider King.

This little museum is making sure that the art and history of the graffiti sticker is not scraped from history.

A narrow passage next to a cafe leads to a courtyard exploding with murals, tags, and paste-ups.

Floating swimming pool within a moored vessel.

Super-heavy Nazi architectural experiment.

A state-of-the-art medical facility from the Imperial era is now a derelict ruin.

An abandoned NSA listening post on Berlin's "Devil's Mountain."

Road signs in Namibia mark the location of one of the five major circles of latitude.

Nearly 2 billion seeds from 38,000 species are stored and processed at this visitable facility in a quiet corner of England.

This haunting stone chasm is a hotbed of mossy rock and English legend.

This tiny little pool is said to be home to a malicious mermaid named Jenny Greenteeth.

In an arboretum with hundreds of memorials to the fallen, this one might be the most poignant.

This Indonesian village was revitalized by a vibrant rainbow paint job.

This stretch of the River Severn where large waves flow against the current is the birthplace of river surfing.

With the touch of a button, you can read a randomly selected short story.

A Nevada mining boomtown that ran out of silver and luck.

This chimerical bridge/tunnel appears to dead end right into the sea.

This ultra-modern wooden boardwalk turns the ocean into a swimming pool.

A 19th-century subterranean reservoir repurposed as a contemporary art cave.

For a couple of months each year this Swedish city turns into a festive neon phantasmagoria.

The site of one of the largest non-nuclear explosions in history, created when a massive bomb dump accidentally exploded.

Cold storage for agricultural biodiversity.

These 17th-century mummies are no longer naturally preserved, but remain on display today.