A state park that once served as an important river crossing, and now offers protected lands for endangered plants and animals.

Featuring the the longest lift span of any vertical-lift bridge in the world.

A hidden passageway now marks the site of an assassination attempt on Ronald Reagan that some say broke a 140-year-old curse.

Cold War intelligence agents monitored communist embassies from an attic in a former pigeon coop.

A clone of a cloned tree that was so important it allegedly had its own guards.

Washington's top-secret Cold War-era doomsday communications tower is located in a small neighborhood park.

The bridge's highly-contested plaque (once again) honors Confederate President Jefferson Davis.

This suburban house is made of dirt, and almost sparked a revolution in home construction.

The 72-foot giant escaped confinement in a large patch of mulch only to be reburied in the sandy shores of the Potomac River.

An allegorical sculpture in Maryland wears the artist’s politics on its trunk.

The world's oldest continuously operating airport was founded by the Wright Brothers.

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

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

An unusual sculpture, an interesting history, in a strange place, for a good cause.

An intricately designed junk art house with four extravagant junk art cars hidden in the suburbs.

Once the supplier for noteworthy projects like the National Cathedral, this old brickworks now lies abandoned.

A historic cemetery with unique artwork, a Civil War fort, and also happens to be the site of the Battle of Bladensburg.

Politicians, bureaucrats, and military officers gathered in this field near the Capitol to settle their disputes with blood.

A 400-foot-tall tall map of Chicago makes this once-ignored building stand out.

A curious collection of miniatures in a quiet corner of the Chicago Children's Museum.

Parking garage where Bob Woodward met Watergate source "Deep Throat."

This brick-lined pedestrian walkway was once a railway tunnel used during the Civil War.

This little brick tunnel built by Confederate forces was used to conduct surprise attacks on the railroad.

The likeness of the Baltimore music icon was unveiled in time for the anniversary of his Senate hearings on music censorship.