A cavernous three-story, 43,800-square-foot basement that was forgotten about for 60 years.

Home to items never before seen by the public.

The United States Capitol's former columns still stand.

Indents in the pavement are all that remain from a grisly death machine in Paris.

The water-powered carriages are long gone, but for over a century this funicular railway has been the fastest route to the highest point in Paris.

The history of radiation is on safe display at the foot of a radiation science laboratory.

This statue was given to France by the United States to commemorate the centennial of the French Revolution.

High atop the Eiffel Tower is a small apartment built exclusively to entertain the science elite and make the rest of Paris jealous.

Millions of numbers carved in glass represent the tattoos forced upon victims.

The remnants of a Gilded Age elegance preserved in the middle of a stark modern tower.

American revolutionaries and British soldiers alike are buried here in the fourth-ever cemetery in Boston.

A more than 260-year-old crypt built on Boston's oldest English burial ground.

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

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

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

Berthed at the Charlestown Navy Yard in Boston, "Old Ironsides" is the oldest commissioned warship still afloat.

Macabre headstones carved with winged skulls, dancing skeletons, and pithy reminders of impending death.

The Boston square dedicated to the dark poet who was born nearby.

This nondescript tunnel has been featured in a number of iconic movies, from “Roger Rabbit” to “Back to the Future.”

Sit at the "Disney table,” where Walt and his team of "imagineers" once dined on the regular.

The famous animator's private station house and man-cave was the birthplace of imagineering.

Historic funicular railway, believed to be the shortest railroad in the world.

Franciscan monks created a facsimile of the Holy Land for North Americans who couldn’t afford the trip overseas.

The vast, legendary catacombs hold secrets much stranger than stacked bones.