Brain collection and database that narrows the gap between man and animal.

This fort down the Potomac from Washington, D.C. was once the only defensive fort protecting the capital.

A remote horde of architectural treasures fit for Indiana Jones.

Built by the patriotic residents of Boonsboro in a single day.

The longest escalator in the Western Hemisphere takes over three minutes to ride down.

A cave on the Maryland border where civilians took refuge during the bloodiest battle of the Civil War.

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

Despite violent work crews and massive delays this abandoned canal tunnel was built to last into the modern day.

Walk a trail through a historic Quaker town that outlawed slavery in 1777 and was a major waypoint on the Underground Railroad.

A blank headstone topped with a pile of pennies marks the final resting place of the infamous assassin.

A priceless collection of the Nation's cryptologic history.

Bizarre Cavern.

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

The site where Poe "in great distress, and ... in need of immediate assistance" likely died.

Crammed into a Baltimore row house is an oddities shop that sells everything from skulls to dead insects.

The trials and tribulations of marking Poe's grave.

It's not hard to see why the historic Peabody Conservatory of Music's library has been described as a "cathedral of books."

The oldest surviving presidential residence in the United States.

Alexander Hamilton’s creation caused quite a bit of controversy.

This beloved marketplace mascot poops money and grants good luck.

The world's third-largest crystal sphere has sat in the Penn Museum since 1927 with the exception of one outlandish theft.

The body of St. John Neumann and his collection of hundreds of relics, on display in a Philly church.

A daily replay of the experiment that proved the rotation of the Earth.

Current docking place of the SS United States, the fastest transatlantic ocean liner.