The beautiful, ornate weather station is the most popular geocache in Salzburg.

Trick water gardens from 1619 featuring a 200 piece mechanical theater powered by water.

A slice of central Asia in the middle of Berlin.

Started as a kitchen garden, now the second largest botanical garden in the world.

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

These banned cigarette vending machines now sell little pieces of pocket-sized art.

Lines from a walking song are etched into a rock in Natural Bridge State Park.

At less than four inches in height, this iconic fictional character is the smallest public statue in all of Moldova.

The last of Philadelphia's wood-paved streets is now a landmark of terrible engineering.

A tour de force of a fountain, memorializing a man who loved fountains more than anything else.

This meticulously extracted nervous system allegedly came from a 19th-century custodian who donated her body to science.

Philadelphia boasts one of the best — and most often overlooked — traditional Japanese gardens in North America.

The enormous 250-room Vanderbilt mansion conceals hidden doors and secret passageways.

Ant sculptures march up the side of what used to be an iconic spot in punk rock lore.

A daily replay of the experiment that proved the rotation of the Earth.

This charming colonial alleyway is one of the oldest continuously used residential streets in the U.S.

Erected in 1697 this Philadelphia bridge is the oldest surviving roadway bridge and perhaps the oldest stone bridge in the United States.

Instruments, apparatus, and rare books all relating to chemistry and its related sciences.

The oldest surviving botanic garden in the United States.

Mural made of 100,000 pieces of hand blown glass, and until recently, the largest glass mural in the US.

Tour the dark and beloved poet's former cobwebbed basement, which may have inspired "The Black Cat."

An ancient Viking runestone hidden in plain view in Stockholm's old town.

This fairytale-like structure is the last turf church ever constructed in Iceland.

In this truly magical place, rent hasn't been raised since the year 1520.