Quirky castle designed by the American actor best known for portraying Sherlock Holmes on stage.

This sacred cavern, 400 feet deep, is home to millions of bats and an ancient burial ground.

A spring-fed pool so deep it's used for scuba diving as well as swimming.

An entire subdivision was accidentally built on a flood plain, resulting in its eventual demolition—but the streets are still there.

A tiny graveyard with a mysterious past.

To honor a beloved Austin radio DJ a neighborhood bridge has been covered in a loving mosaic.

This unassuming North Austin neighborhood was built to test the novel idea of home air conditioning.

The upstairs reading room is packed with millions of rare books, literary manuscripts, and historical treasures.

This eclectic, mosaic-clad home includes a bamboo ping-pong loft and a "Whispermaphones" intercom.

A view-altering observatory at the University of Texas.

This eclectic Austin curiosity shop is home to all things strange and unusual.

DIY collection of eclectic holdings.

Continuing the tradition of the dime museum in style.

The mummified relics of an American missionary.

La Monte Young and Marian Zazeela's "Dream House" will immerse you in an ever changing world of sound and light.

Hidden in plain sight on the Hudson River is an abandoned train station where nature has taken over.

A strangely angled West Village home is the only monument to an explosion that took the lives of three American revolutionaries.

New York City's only preserved family home from the 19th century.

New York City's smallest piece of private property.

This slender three-story building has also had several famous residents.

A terrific purveyor of natural history objects and curios.

The oldest living tree in Manhattan comes shrouded in sinister legend.

Twenty-three trees, each paired with a basalt stone, line a street in Chelsea, continuing an urban project started by German Fluxus artist Joseph Beuys.

Rummage through this sunken ship, but leave your scuba gear at home.