This sprawling bookstore spans four floors and has more than a million books in stock.

The Beaux-Arts aquarium boasts a vast collection of saltwater and freshwater fish on an island in the Detroit River.

One of the Seven Wonders of the Modern World holds the world's tallest metal staircase.

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

A rather vulgar example of the transition from Latin to the Italian vernacular.

A Nesting Doll of Churches.

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

Cryptic messages embedded in the New York City sidewalk.

A celebration of capitalism in Midtown.

Ride the subways of yesteryear.

This cemetery has graves dating back to the 17th century, including the city's oldest carved tombstone and an ominous cryptogram.

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

This bar named after the world's first mixed cocktail was home to one of New Orleans' most notorious politicians.

In 2010, Nicolas Cage purchased two plots in this cemetery using one to construct this strange pyramid mausoleum.

The final resting place of New Orleans' most famous voodoo priestess.

A daily replay of the experiment that proved the rotation of the Earth.

World's first "penitentiary," meant to be humane, drove men insane.

This water-tower-turned-high-end-apartment building was once the site of an early Nazi concentration camp.

Thousands of coffin-like pillars make up this controversial Holocaust memorial.

An eerie, derelict amusement park in Berlin.

This city square is home to Amsterdam's oldest church and a statue honoring Dutch sex workers.

Each August, one of the largest religious (and food) celebrations in the country is held in Boston.

A former waterfront market is now in the center of town due to some interesting Boston engineering.

To find the "unicorns of the deep" you've got to go downstairs.