This small monument to the great inventor contains a time capsule and a Wi-Fi hotspot.

This large copper bolt represents the benchmark for measuring sea levels in most of Europe.

No one's quite sure why there's a metal megaphone bolted on two rocks in the middle of the Mojave Desert.

The stone marker that Mason and Dixon placed at the eastern end of the famous north-south border they surveyed.

Is this the most Portland place ever?

A clerical error gave rise to this imaginary micronation in the southwestern corner of Estonia.

An army of sleeping knights sculpted by a self-taught local artist beautifully depict an old Czech legend.

Where artisans use centuries-old techniques to build traditional Arabian ships.

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

Over 100 towers were built in Bologna during the Middle Ages, but only 22 survive.

The origin of this mechanical boy was a mystery until he revealed his maker by writing it in perfect cursive.

All that's left of the quintessential "cabin in the woods."

The U.S. Fish Commission’s effort to mass produce carp.

This grubby wall is said to be one of the Earth's esoteric energy centers.

This sandwich shop has a century-old elevator behind a sheet of plexiglass.

Bullet holes in the church wall are a reminder of the violence that followed the assassination of a high-ranking Nazi officer.

These excavated burials from the Tarim Basin are wrapped in mystery.

This rickety old shed hides a trove of secondhand literary treasures.

These official units of measurement—including chains and perches—lie hidden beneath tourists' feet in a popular London hub.

This marvelous array is one of the largest collections of mechanical instruments in Europe.

The world's largest private telescope collection hides in a secret wing of a Dutch auto museum.

A hidden gem of a museum that lets you search for your own fossils.

A metal ring in the middle of the road marks the exact spot where the Soviet satellite crash-landed in 1962.

A tribute to an iconic act of defiance from the Croatian War of Independence involving a small car.