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.

The oldest surviving one-room schoolhouse in Montgomery County, Maryland.

This ruined quarry once produced the distinctive red sandstone used for construction projects in Washington, D.C.

The ruins of this long-abandoned unsuccessful gold mine can still be found.

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

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

A secretive collection featuring objects that were designed specifically for U.S. intelligence operations.

The longest escalator in the Western Hemisphere takes over three minutes to ride down.

FDR's Art Deco hospital tower was hopelessly inefficient.

This mighty white oak in Bethesda survived both the American Revolution and the construction of Washington D.C.'s metro red line.

This propitious plastic porcine has been petitioning park visitors to pick up after themselves for more than 50 years.

This massive wooden building contains a giant Buddha, healing pillars, and tame deer wandering the grounds.

A shrine contains nearly 200 statues of the Buddhist deity Jizo, dressed in bibs by parents who have lost a child.

The 10,000 Torii shrine.

1,001 carved statues of the Buddhist God of Mercy, each with a unique face.

This 14th-century temple is also known as the "Temple of the Golden Pavilion" for its gorgeous gilded reliquary hall.

The quintessential Japanese rock garden has existed for more than 500 years.

Giant pagoda houses the car that drove Thích Quảng Đức to his death by self-immolation.

A memorial dedicated to the victims of the My Lai Massacre.

The lavish temple of the Cao Dai religion that includes Buddha, Mohammed, Joan of Arc, and Victor Hugo.

Artifacts and memories from the Vietnam war, located in a place that experienced it first hand.

Meant to be a lavish presidential home, the palace became a symbol of the fall of South Vietnam.

This French colonial post office is arguably the grandest in all of Southeast Asia.