Soldiers were buried next to Lee's house in the center of Arlington Cemetery to dissuade the general from reclaiming his property after the war.

The maritime museum that boasts the largest nautical library in the western hemisphere.

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

Headquarters of the legendary clairvoyant's readings, spiritual hospital, and massage school.

At 207 feet, one of the world's longest continuous escalators.

America's first public mental health facility.

An organ located deep within a cave, whose "pipes" are the geological features of the cave itself.

A sacred site for Native Americans surveyed by George Washington and owned by both King George III and Thomas Jefferson.

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

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

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

A girls' boarding school inspired by the Chicago World's Fair, once abandoned, now restored to strange and scenic glory.

The land is home to swimming ponies and a legendary 18th-century treasure.

Eighteen miniature death-scene dioramas.