A Civil War fort in the middle of Washington, D.C. has been swallowed by a forest.

The fastest transatlantic ocean liner sat abandoned in a Philadelphia shipyard for decades.

Holding multiple historical boats and an entire 19th century village, this New England attraction is the largest maritime museum in the world.

The author of Uncle Tom's Cabin was neighbors with Mark Twain while living in this Connecticut home.

"A hideous albatross in the Hudson River Valley."

This tiny church near Sleepy Hollow contains Henri Matisse's last work, a rose window, and nine windows by Marc Chagall.

The home of one of America's most wealthy industrialists is now a historic site that remembers a more decadent time in the country's history.

A world-class collection of mechanical musical instruments and automata.

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

Graffiti, cars, and religion combine to create this jungle of scrap in the Nevada desert.

An abandoned Jazz Age dream home and con man's hideout in Death Valley.

The lowest point in North America is home to an undrinkable pool surrounded by fields of geometric salt flats.

France's most famous cemetery, with some of its most curious tombs.

This modest marker near Notre Dame identifies the very center of Paris.

Ironically this massive termite is the mascot for a company that is acclaimed for killing his kind.

"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."

This landmark cemetery in Boston was created more than 300 years ago.

The site of Paul Revere's historic two lantern warning.

A centuries-old church stands as a testament to Boston's "father of architecture."

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

Unicorns, elephants, and bears, oh my!

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

A clock set into the concrete outside a Manhattan jeweler has been telling time underfoot for over a century.

Unrepaired walls from a 1920 anarchist bomb attack.