A 98-room castle in the middle of Toronto that bankrupted a 19th century electricity multimillionaire.

This unusual building straddles two countries.

The thousands of shades on display — some toxic, others impossibly rare — are a library of more than just color.

This miniature feudal castle was built on a whim to honor a US Navy pioneer.

An eccentric inventor's castle home with its own indoor weather system.

The world's largest rotating world.

This tiny patch of arid sand sits in one of the greenest states in the United States.

For two weeks every June, fireflies in the Smoky Mountains perform an astonishing light show.

A humble homemade ride attracts visitors from around the globe to this small Midwestern town.

Hidden in a metro shop under a shopping mall, this small museum tells the story of one of the world's largest urban transit systems.

This town near Nagasaki is flecked with fruit-flavored bus stops.

A grand New York post office that is home to mailman Santas, scraps of postal history, and a pneumatic mail system.

Travelers exchange letters with woodland creatures at this mini post office.

A stairway to heaven, or to nowhere at all.

The Atlantis of Cape Cod reemerges during the lowest of tides.

An immersive environment that is part haunted house, part choose-your-own-adventure, and part jungle gym.

In the middle of the desert, miles from any human life, sat an anomalous pay phone that still magically answers your calls.

Manhattan's Thirteenth Avenue was made on landfill then deliberately destroyed — apart from one small, obscure block.

Located in the thermoelectric factory that once powered the entire city, this Portuguese museum is shockingly fascinating.

Part modern art project, part traditional chapel, this see-through church is only substantial from the right angle.

Somewhere between an art studio and a print shop, this artists storefront is a house of worship devoted to type.

This massive stained-glass masterpiece is thought to be the largest Tiffany dome in existence.

Marvel at this turn-of-the-century masterpiece that has been turned into a rather stately supermarket.

Perched on a spindly rock spire in a Greek archipelago, this lighthouse would make a perfect wizard's tower.