The only structure left with direct ties to the Salem witchcraft trials of 1692.

An enormous, inside-out glass globe built in 1935.

The U.S. government built the million-pound stack of steel during the Space Race.

America's first nuclear-powered merchant ship is now a time warp to the atomic age.

This golfball sized platinum iridium cylinder is the official starting point for all national weight calibrations

One of the only memorials dedicated to journalists who died in combat.

The stone marker that Mason and Dixon placed at the eastern end of the famous north-south border they surveyed.

The development and impact of electronic media showcased in a picturesque farmhouse in Maryland.

A haunting exhibit in a wildlife refuge center highlights threatened species and the conservation efforts needed to save them.

A faded sign from the 1920s remembers Baltimore's resistance toward banning alcohol.

The Forest Service's surprisingly sophisticated collection of wildfire prevention art features America's most beloved bear.

This scenic Maryland park was the site of one of the worst prison camps of the Civil War.

The shelves in the back of this thrift store are devoted to saving, not selling, retro tech.

This simple convenience store sits on the location where the Ouija board was named—and has a plaque to prove it.

A Civil War Museum with some notable medical antiques.

An FDR-era tuberculosis sanatorium has stood abandoned in the suburbs of the U.S. capital for over 30 years.

This dig site outside D.C. is known for its exceptionally high density of baby dinosaur fossils and dinosaur eggs.

Walk through the history of American pop culture.

A priceless collection of the Nation's cryptologic history.

The man who first patented the Ouija board rests in peace beneath a headstone that playfully reflects that achievement.

An astounding collection of medical specimens, including bits of President Lincoln.

The trials and tribulations of marking Poe's grave.

This abandoned asylum was once a state of the art facility before devolving into one of the most deadly mental institutions in American history.

As communication goes completely wireless, this Maine museum remembers all the wires that got us to this point.