Secret refuge and museum of the Duke of Florence.

"A hideous albatross in the Hudson River Valley."

These medieval skyscrapers dominate the skyline of this small Tuscan town.

One of the world's longest murals depicts the history of diversity in Los Angeles.

A dismembered holy head stares out from her beautiful reliquary at the St. Dominic Basilica.

Commemorating the spot where the famous scientist fed his pigeons.

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

The famous author's cottage hideaway.

Medieval torture techniques with a modern conscience.

This historic address is home to the beloved ball and is an almost totally empty building among the most expensive real estate in the world.

A bit of retro transportation flair preserved in the world's largest department store.

Portlandia is the second-largest copper repoussé statue in the United States.

The New York hotel where tragic visionary Nikola Tesla spent his final hours, destitute and alone but for the pigeons.

The "Seinfeld" diner.

Avoid gangster interaction while window-shopping.

An artist's cute bronze subway sculptures belie his violent artistic past.

One of the last Jazz Age "Wonder Theaters" in New York City.

By day this New Orleans square is for pedestrians, but by night it is a kingdom of kittens.

Built as a gift to the hottest tastemaker of the time, these hidden quarters remain an Art Deco showpiece.

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

Over 50 exquisite hand-painted Renaissance maps decorate a Medici storage room.

Curious crustaceans support an obelisk from ancient Egypt that now stands in modern-day Central Park.

This mosaic dedicated to John Lennon was tended for years by a Beatles super-fan.

The land is home to swimming ponies and a legendary 18th-century treasure.