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

One of the oldest anatomical theaters in the U.S. still in use was once the site of an infamous cadaver riot.

Fiji mermaids, mummified remains, and recreated cryptids are among the morbid oddities at this Maryland museum.

A meandering boardwalk across the bogland leads to a "stairway to heaven" with sublime views.

Fittingly, America's museum of architecture is itself a magnificently designed old building.

A nostalgic bibliographic gem.

Long-abandoned trolley tunnels just a mile away from the White House are turning into an art space.

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

The largest retailer of seashells in the world.

A science teacher's dream.

With over 100 jam-packed rooms to explore plus elaborate tea services and events, the Mansion on O Street is a hidden treasure.

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

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

An original apothecary from 1792.

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

This lonely waterfront memorial to the men of the Titanic was erected by the "Women of America."

The beloved statue at the National Academy of Sciences is oh so inviting to sit on.

The United States Capitol's former columns still stand.

A monument in Washington D.C. marks the spot from which all other roads were supposed to stem.

The first purpose-built art gallery in the United States is once again open as a center of craft arts.

America's Most Wanted's set resides in this tribute to the history of crime and punishment.

Giftshop catering to cryptozoologists and anyone with a sense of humor.

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

One of the dwarven trees dates back to 1625 and survived the Hiroshima bombing.