A hidden bathhouse in one of Stockholm's oldest and busiest neighborhoods is open to anyone who can find it.

L.A.'s oldest operating bowling alley is a beautifully restored homage to its speakeasy days.

A breathtaking 19th-century trail overlooks Lake Tahoe.

This long-distance walking route follows the Prime Meridian line as it passes through England.

A series of 33 stone markers maps an ancient 55-mile transportation route.

Fifty years after a “blast blasted blubber beyond all believable bounds,” this idyllic natural area commemorates the carnage.

Live data is transmitted from the Atlantic coast to instantly recreate the ocean waves in this fountain at the NOAA headquarters.

This automated sculpture of two men peeing will spell out text messages with their micturition.

A mysterious carving from 17th-century London seemingly depicts a young boy sitting on a bread basket.

Ice cream stand, snack bar, and time capsule of milk conveyance.

The oldest hotel in the world has been operated by the same family for over 1,300 years, even catering to samurai.

Coastal dunes, site of buried Egyptian movie set and former utopian colony.

A science teacher's dream.

Private collection of art inspired by cabinets of curiosity.

The old Niles Canyon Aqueduct in the San Francisco Bay Area is a bemusing and secret trail through nature for wayward travelers.

World's largest collection of serial killer artwork and other macabre exhibits.

A tiny museum housed in a New York freight elevator specializes in the "overlooked, dismissed, or ignored."

A modern mechanical planetary system, part of a 10,000 year clock.