This lavish room at NYC's French Embassy is a rare relic from the end of the Gilded Age.

A replica of a 7th-century church hides in plain sight in the middle of the concrete jungle.

The former hotel where Tesla invented the radio.

A Manhattan courthouse hides a small but scathing memorial to Holocaust injustice.

A three-story copper skybridge connects two Manhattan buildings with Art Deco luxury.

Hidden in an ordinary Midtown building is a one-room museum dedicated to the greatest escape artist.

A Pythagorean funhouse that tries, successfully, to prove that math is the coolest thing ever.

Manhattan’s Battery Park has a whimsical carousel full of spinning, glowing fish.

New York's oldest magic store.

The famous artist couple lived and worked here, in two different houses separated by a bridge.

This fantastical house shaped like a seashell brings aquatic design to architecture.

Part bookstore, part café, and part forest.

A gargantuan crystal kingdom.

At high tide this strange footbridge appears to have no purpose whatsoever.

A curious collection of mechanical moving figures.

An English artist has turned an unassuming ex-council house into a time-lost house of mystery.

A harem-inspired Moorish fantasy design in a Victorian-era Welsh castle.

The names Lúthien and Beren can be found inscribed on the shared grave of the famous writer and his beloved wife and muse.

The pioneer of psychoanalysis spent the final year of his life here, still seeing patients on that famous couch.

This magical museum celebrates the life and work of a seminal children's book writer (and occasional spy).

A local tree surgeon has created a whimsical walk full of carved tree stumps near Scotland's Loch Lomond.

This beautiful "lagoon" is actually a toxic soup filled with cars, carcasses, and trash. When warnings couldn't stop people from going for a dip, the town dyed it black.

Fantastically decorated underground chambers built in the 1760s.

One of the largest sculpture collections in the U.K. features history's greats, from Bob Dylan to Galileo, in bronze.