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

The most accurate timepiece in the world.

When it comes to handsignals (and colonialism) rock always beats scissors.

The span is crooked and made from two older recycled bridges.

A painfully obvious spy house sits right across the street from the Russian Embassy.

The only Civil War battle in Washington D.C. took place near this highest natural point in the city.

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

She stares out across six lanes of traffic, clutching a musket and infant with determination.

FDR's Art Deco hospital tower was hopelessly inefficient.

At Washington's Dulles Airport is a satellite museum (no pun intended) with three quarters of a million square feet of aircraft history.

These unusual rooms on wheels are holdovers from the 1960s.

One of the oldest standing structures in Montgomery County, Maryland.

Every drop of D.C. tap water flows through this old waterworks.

These abandoned waterworks are crumbling into the Potomac River.

Once home to seven different roller coasters, Glen Echo has undergone many transformations since its founding in 1891.

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

Proto-CIA agents trained with grenades in the sand traps and fired machine guns from the fairways.