This unassuming Massachusetts residence was built with a trap door to hide escapees on the Underground Railroad.

On top of Gibbet Hill lie the ruins of a lavish turn-of-the-century estate that never quite came to be.

A short nature trail winds through the greatest works of poet Robert Frost.

A gas station and a state sign commemorating the most famous claims of extraterrestrial abduction.

This picturesque abandoned home is rumored to be a spite house.

A historic custom house with ties to George Washington is now a shrine to local nautical history.

A diminutive plaque recalls the treetop sniper who almost killed Abe Lincoln.

Henry VIII's forgotten castle was built by the gunpowder-obsessed king to be defended solely by cannons.

A beautiful ruin of a 14th-century Plantagenet castle built by a medieval mercenary.

This remarkably intact, 260-year-old cargo ship is only visible at the lowest of spring tides.

A replica of the straw hut where Vladimir Lenin lived in hiding, disguised as a hay farmer, in 1917.

An art museum inside an active factory.

An unusual collection of self-made musical instruments and unique noises.

Inside the world's largest seed bank, WWII botanists elected to starve to death rather than compromise their collection.

An ever-growing literary collection housed in the apartment where the Russian author penned his final novel.

A city block packed with whimsical sculptures that seem to be plucked from a tiled fantasy world.

This Russian museum stresses the importance of keeping clean and even holds one of Pavlov's dogs.

A 250-year-old timepiece-automaton adorned with golden mechanical birds, which still sing to this day.

Palace where the nearly un-killable Rasputin was murdered.

A tiny museum in Esperance, Australia, displays a bunch of space debris from NASA’s Skylab.

An important piece of history from mankind's journey to the moon sits in the lobby of a government science lab.

A three-piece musical sculpture installed between the subway tracks at Kendall Station near MIT.

One of the last remaining movie theatres in the country that features a rear-projection system.

A Harvard-area eatery preserves the uncovered tiles of its century-old predecessor.