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.

Giftshop catering to cryptozoologists and anyone with a sense of humor.

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

This leafy estate is worth $18 million and is so grand it has two mailing addresses.

This grisly headstone doesn’t seem to be resting in peace.

An Industrial Revolution-era public work that purified water using nothing but sand.

The towering figures were created from the cemetery's fallen old-growth trees.

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

The United States Capitol's former columns still stand.

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

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

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

Tiny observatory made big contributions to the study of the Earth's motion.

An overlooked oasis of quiet on the grounds of Washington's monumental basilica.

Enormous piles of historically significant stones, dumped by Congress in a forest, and abandoned for 60 years.

Largest Roman Catholic church in North America.

A lovely aquatic park built by a one-armed Civil War veteran who made a fortune from lotuses.

A memorial to a shareholder activist feared by CEOs around the United States.

A haunting tribute to pioneering photographer Clover Adams.

Franciscan monks created a facsimile of the Holy Land for North Americans who couldn’t afford the trip overseas.

The final resting place of the tragic king and queen of the Jazz Age is tucked away in a small Maryland graveyard.

The wooded estate of the Forest Service employee responsible for D.C.’s cherry blossom trees.

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