Only hotel where you can legally launder money.

The most loyal of little dogs, or a Victorian era publicity stunt?

360° views of the city plus five floors of optical illusions and hands-on science.

This 17th-century street hidden beneath Edinburgh was once a breeding ground for the black death.

Ruined 11th century abbey built by King David I in Edinburgh, Scotland.

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

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

Built hundreds of years ago this downtown iron barrier once protected a much despised king.

This sculpture by artist Fritz Keonig survived the 9/11 attacks and now stands as a monument to the victims.

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.

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

The ancient past meets the retro-future at these dinosaur tracks that are protected by a geodesic dome.

The highest point in Connecticut was incorrectly memorialized before surveyors discovered the actual spot.

The former home of Samuel Clemens and family remembers the happiest period of the author's life.

Over 50 whirling pools left behind from the glacial age.

A massive sustainable farm designed by the mastermind behind Central Park.

This lovely, if imposing, piece of Canadian gothic is possibly the most photographed hotel in the world.

The world's largest rotating world.

A steampunk wonderland that preserves America's history of industrial innovation.

The world's largest piece of copyrighted artwork.

Civil War-era Fort designed to withstand invasion and attack, with tricky traps called "murder holes."

Civil War Fort on an island in the Boston Harbor.

On a former island, this old fortification once used to protect the Boston Area and started Edgar Allan Poe in his military career.

This monument on Breed's Hill proves that one of the most famous battles of the Revolutionary War is misnamed.