Fascinating museum dedicated to the under-appreciated medical history of urology features some wince-inducing devices.

This abandoned sea fort has become an accidental bird sanctuary.

There's a crumbling old mansion inside the Smithsonian National Zoo.

A surprising, but overlooked example of geology in the middle of the nation’s capital.

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

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

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

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

Giant acorn-shaped 19th century gazebo from which suburban Washingtonians gazed upon the original "silver" spring.

Live data is transmitted from the Atlantic coast to instantly recreate the ocean waves in this fountain at the NOAA headquarters.

This grove was planted more than a century ago by the War Mothers of World War I.

The haunting "Hell House Altar" is one of the few remnants of an abandoned college that has been a magnet for local legends.

Once part of a dam servicing an early 19th century grist mill, the tucked-way falls are a tricky-to-find urban oasis.

An eerie, decaying ghost town destined to fade into the forest.