The highest point in Washington state is a volcano covered in glaciers.

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

Lie in a hammock where George Washington stood.

This tipsy office building in downtown Prague was originally called “Fred and Ginger.”

The tech giant built three enormous glass orbs in Seattle so employees could work inside a rainforest greenhouse.

Copenhagen's celebrated theme park and gardens.

This Wall Street bar was once a hub of revolutionary activity where Washington famously bid farewell to his troops.

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

This palatial botanical garden is home to one of the largest pipe organs ever installed in a private residence, and a piece of Wood's cycad.

London's old-school healing garden.

The last moments of the ill-fated Pompeiians, frozen forever in plaster.

The engineering wonder and pleasure dome of a much-maligned emperor still holds undiscovered secrets.

Lady Liberty's first beacon of enlightenment is now displayed in a museum near the statue.

The ruins of a Duke's bucolic dream, where camels once roamed alongside "Dutch" windmills and faux-Italian vineyards.

The 340-year-old house that inspired the classic Nathaniel Hawthorne novel.

A cluttered and astounding collection of antiquities and curiosities.

A 2000-year-old Roman amphitheater lies just below Guildhall Yard.

The only Bahá'í house of worship in North America and one of only a handful worldwide.

Stockholm's decidedly unique public transit system has doubled as the world's longest art gallery for decades.

2300-year-old Roman road connecting the empire.

This 1920s Dutch barge is now a floating bookstore.

Medieval museum built over Roman baths that features famous tapestries of a lady and a unicorn.

Once the tallest building in the world and the site of "the highest dinner ever held in New York" this building now holds the most expensive penthouse in the city.

The quintessential Japanese rock garden has existed for more than 500 years.