This charming colonial alleyway is one of the oldest continuously used residential streets in the U.S.

A layered tribute to the work of mosaicist Isaiah Zagar.

America's most famous museum of medical oddities is home to the remains of Albert Einstein's brain.

The world’s first penitentiary, meant to be humane, drove men insane.

The location where the famed author and abolitionist began his journey to freedom.

Hidden within an idyllic suburban garden is a memorial dedicated to the victims of a terrifying spree of killings committed on U.S. soil.

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

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

This hidden treasure provides a charming access point along the south side of Baker Park.

The smallest covered bridge in Maryland.

Built in 1815, the stabilized ruins of the grist mill and sawmill are now gated, but interpretive displays on the features and functions of the mill preserve its history.

FDR's Art Deco hospital tower was hopelessly inefficient.

This advertisement for talcum powder was painted on the rock face and has since defied removal.

She stares out across six lanes of traffic, clutching a musket and infant with determination.

The headquarters of the Audubon Naturalist Society is a small slice of heaven for nature lovers.

The bridge's highly-contested plaque (once again) honors Confederate President Jefferson Davis.

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

The 72-foot giant escaped confinement in a large patch of mulch only to be reburied in the sandy shores of the Potomac River.

This historic lighthouse was well known for the large number of women who served as its keeper.

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.

A lawn full of retired spacecraft on display at one of NASA's first research labs.

A star fort along the C&O Canal in western Maryland that protected America in three wars.

An isolated island home to one of the oldest English-speaking communities in the region and Maryland's state dessert.