This English-inspired Maryland garden is home to acres of opulent plant life including bushes shaped into an entire fox hunt.

A swimming hole in the historic industrial quarry that supplied the marble for the Baltimore Washington Monument.

A museum dedicated to exhibiting remarkable outsider art.

This bug-eyed water wheel uses the power of the Sun to clean up Baltimore Harbor.

Walk through the history of American pop culture.

Largest Roman Catholic church in North America.

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

The "lovely red Vega" of the legendary record-settling pilot.

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

Washington's iconic carousel has a nice piece of Civil Rights history.

A monument in Washington D.C. marks the spot from which all other roads were supposed to stem.

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

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

These old doors are covered in the signatures of Rehoboth Beach artists dating back to the 1930s.

What began as an art installation is now the private drinkhaüs for a brewery's employees.

The tallest The Church of Jesus Christ of Latter-day Saints temple in the world soars above the Beltway.

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

A Civil War fort in the middle of Washington, D.C. has been swallowed by a forest.

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

The iconic D.C. restaurant where the Cuban Missile Crisis was negotiated, now a Walgreens.

An obscure federal monument honors the French diplomat who served as Ambassador to the U.S. during WWI.

The most accurate timepiece in the world.

Fittingly, America's museum of architecture is itself a magnificently designed old building.

The site of the climactic scene from the classic horror film is now a historic landmark.