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

An extensive, if one-sided, history of U.S. law enforcement's war on drugs.

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

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

You could be standing at the site of one of D.C.'s most fatal tragedies and not even know it.

One of the largest collections of Catalan literature and cultural materials outside of Spain, created by a community of 1960s expats.

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

The site where Poe “in great distress, and ... in need of immediate assistance” likely died.

Once America's tallest structure, now a Baltimore landmark.

The most accurate timepiece in the world.

The semi-reclaimed ruins of this canal were once part of an ambitious plan to reroute the mighty potomac.

A double agent hid information for the Soviet Union beneath this bridge for more than 20 years.

Need a hardcopy of the 50-title Code of Federal Regulations? This is the place.

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

One critic described it as "middle Mussolini, early Ramses, and late Neiman-Marcus." Another called it an architectural "natural disaster."

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

A historic ruin just 20 feet away from a busy highway onramp.

One of the only memorials dedicated to journalists who died in combat.

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

"Congress may voluntarily remain in session throughout the summer, in order that our Congressmen may be protected from the intolerable discomforts and dangers of the ordinary outdoor weather!”

This pre-Revolutionary War grist mill ground corn and flour for soldiers in seven American wars.

This Virginia railway overpass is said to be haunted by a serial killer in a rabbit costume.

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

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