This island castle contains enough secret passageways to support a season of Scooby-Doo episodes.

Located on the banks of the St. Lawrence River, this mansion is home to a massive art collection.

Canada's oldest railway tunnel is illuminated in a rainbow of color as it passes under the streets of this small city.

The building that inspired Shirley Jackson's "The Haunting of Hill House."

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

The original toys that inspired the beloved children's stories are on display at the New York Public Library.

This Gothic castle was inspired by Erik the Red's Viking residence at Brattahlid in Greenland.

"the sweltering inhabitants of Charleston and New Orleans, of Madras and Bombay and Calcutta, drink at my well . . . The pure Walden water is mingled with the sacred water of the Ganges."

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

No one really knows how these old hobby horses got here, but the herd keeps growing.

This tower pays homage to a legendary Viking fort established in Massachusetts that never really existed.

This small shop walked so America could run on Dunkin'.

Ralph Waldo Emerson spent two years living here decades before it became a Frederick Law Olmsted-designed park.

Museum dedicated to awful artwork.

This former Masonic hall has been turned into an art project that uses even more metaphysical iconography.

One of America's most historic homes also holds a startling literary legacy.

Radical Bookstore and Community Space.

This tiny, painted door at the base of a tree stump has been a fixture of the Harvard University campus for decades.

Two thousand artifacts from around the world collected by one woman who loved to travel.

This tower commemorates the spot where George Washington hoisted the Grand Union flag.

This impressive Boston holy house is the American mecca for Christian scientists.

This upscale streetwear store is hidden behind a fake Snapple machine in the back of a deli.

19th-century operating theatre in which the use of ether was first demonstrated - plus, a skeleton and a mummy!

The history of the tea trade is told in bas-relief on this historic pair of Boston doors.