Behind an abandoned storefront is an example of pioneering 1930s gas station architecture.

With over 100 jam-packed rooms to explore plus elaborate tea services and events, the Mansion on O Street is a hidden treasure.

This restaurant has been a haven for D.C.'s LGBTQ community since the 1950s.

A spectacular tribute to statesman and philanthropist Andrew Mellon.

An echo chamber with a waterfall wrapped around its base at the Embassy of Canada in Washington, D.C.

A muscular Art Deco monument represents the struggle between regulators and unbridled markets.

A secret greenspace hides atop a Capitol parking garage.

A hidden gem on the lawn of the U.S. Capitol Building designed by landscape architect Frederick Law Olmsted.

After his presidency, George Washington planned to live only a few blocks from the Capitol building.

The tunnel under the Capitol Building where Congress takes out its trash.

An unassuming, powerful monument north of the U.S. Capitol bears witness to the resilience of Japanese Americans during a time of grave injustice.

A 1,100-ton train fell through the floor in 1953. Workers got it patched up in just 72 hours.

An easily overlooked memorial to a Ukrainian famine-genocide that killed over 4 million people.

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

One of the first Second Empire-style buildings constructed in North America.

Largest Roman Catholic church in North America.

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

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

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

The first woman to become a member of the parliament of Iceland.

This massive redwood tree has stood in Northern California for nearly 2,000 years.

Under the shadow of its towering parent tree, a rare specimen of sequoia produces ghostly white leaves.

This massive solar generating facility in the Nevada desert has been plagued by difficulties.

Inscribed on the gate are the names of 29 figures from the University's first five centuries.