The bunker where Hitler took his own life is hidden under this deliberately ordinary parking lot.

Thousands of coffin-like pillars make up this controversial Holocaust memorial.

A tour of underground Berlin takes you through WWII air raid shelters and tunnels used to smuggle people out of East Germany.

These former Nazi anti-aircraft towers offer a singular view of the north of Berlin in the summer, and a sanctuary for bats in winter.

Cold war icon and onetime "hole" in the iron curtain.

A largely forgotten and touching neoclassical marble fountain overlooking a bear mound effigy.

This statue honors the author's groundbreaking family story.

This isn't your average roadway—it's actually a National Park and a transportation pioneer.

The unique traffic pattern named for an influential urban planner is also known as the Pedestrian Scramble.

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

This stately building in Alexandria, Virginia was built by Freemasons to honor one of their most famous members.

This rare triple-jurisdiction drawbridge passes through Virginia, Maryland, and Washington, D.C.

A river with some unusual, and occasionally dangerous, habits.

This grave marks the passing of a historic Jane Doe whose identity remains a mystery to this day.

This mysterious structure by the Washington Monument is a flood barrier designed to protect the White House against rising waters.

An original apothecary from 1792.

A former major munitions plant that has been converted into a sprawling art space.

This small pedestal marks the spot of the first lot of land sold in Alexandria, Virginia in 1749.

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

A much-maligned monument to teetotalism.

The 28,000-year-old specimen is remarkably intact.

D.C. once had its own tiny rival to the New York Stock Exchange.

Legend has it that President Grant’s frequent drinking in the lobby gave rise to the term “lobbyist.”

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