The naval commander’s proudest moment in battle is memorialized in this unique tomb at Arlington Cemetery.

Soldiers were buried next to Lee's house in the center of Arlington Cemetery to dissuade the general from reclaiming his property after the war.

The controversial urban planner who designed Washington, D.C., was buried in Maryland, and can presently be found in Virginia.

Born a slave on the Arlington estate, Parks dug the first graves at Arlington National Cemetery, and was buried there, too.

The Pentagon sits on a former island that was in Virginia at low tide and D.C. at high tide.

Please don’t anchor your boat onto the Department of Defense’s underwater data cables.

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

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

An overlooked memorial honoring the local Washington residents who died in World War I.

There’s a hidden military meme engraved on the World War II Memorial.

The U.S. Fish Commission’s effort to mass produce carp.

A tiny monument to the unsuccessful attempt by Thomas Jefferson to place the prime meridian in Washington.

There's a 12-foot-tall replica of the Washington Monument hidden under a manhole nearby.

The monument's pointy aluminum tip has been melted down by repeated lightning strikes.

Daredevil repair workers can worm their way out the access hatch, loop ropes over the apex and rappel down the monument.

An obscure public service from the U.S. government that redeems burnt, moldy, and soiled old greenbacks.

Art deco landmark on the outskirts of Washington, D.C.

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

A tribute to the pop culture icon overlooks this Washington D.C. intersection.

A celebrity from the late Cretaceous period.

Through the decades, Black music stars have performed at this historic hub for music and the arts.

Washington D.C.'s most famous pianist, composer, and bandleader still tickles the ivories outside Howard Theater.

A pair of black granite tails dive into a sea of grass in landlocked Vermont.

This cemetery has graves dating back to the 17th century, including the city's oldest carved tombstone and an ominous cryptogram.