This rare triple-jurisdiction drawbridge passes through Virginia, Maryland, and Washington, D.C.

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

A former major munitions plant that has been converted into a sprawling art space.

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

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

The United States Capitol's former columns still stand.

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

This isn't your average roadway—it's actually a National Park and a transportation pioneer.

The romance of early commercial flight still fills this Art Deco destination.

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 actual model from the original "Star Trek" series is now on display at the National Air and Space Museum.

A tiny piece of the Moon is embedded in this stained glass masterpiece.

This imposing Masonic temple a mile from the White House was the first public library in Washington, D.C.

A hoard of sky catalogs, astrophysical journals, even the works of Galileo and Copernicus.