This abandoned iron furnace was one of the first to use coke—a type of high-carbon fuel—to make iron.

A giant time capsule not scheduled to be cored until 2040.

Locals call this magical moss-covered walkway the "Emerald Path."

A pyramid commemorates the birthplace of James Buchanan, the 15th president of the United States

A small granite block at this monument's base is the only part of Lincoln's Tomb outside of Illinois.

Penn State's giant bug collection.

This twice-relocated "Usonian" home is among the smallest built by master architect Frank Lloyd Wright.

The only Civil War battle in Washington D.C. took place near this highest natural point in the city.

This forgotten boat elevator was an engineering marvel in its heyday.

This suburban house is made of dirt, and almost sparked a revolution in home construction.

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

A whopping 14,000 copper coins cover this miniature fighter jet.

An out-of-place Air Force radar dome is all that denotes this park as a former missile launch site.

An eccentric company offers eccentric millionaires the opportunity to have spaceflight-related experiences.

The last of nine massive kilns that produced many of the red bricks for buildings in Washington, D.C. and northern Virginia in the early 20th century.

Standing for over 200 years, the abandoned home of a Revolutionary War hero and later a succession of prison superintendents.

A double agent hid information for the Soviet Union beneath this bridge for more than 20 years.

Located at the former Lorton Prison the Lucy Burns Museum tells the story of the 91 year history of the prison including the dark chapter of its involvement in the women's suffrage movement.

This museum sits on the site of a decommissioned military communications base.

Collecting 700 years of mechanical death-dealing, the NRA's sprawling gun museum is a revealing testament to the American obsession with armament.

Burke’s oldest cemetery also houses the victim of the county's grisliest murder.

This Virginia railway overpass is said to be haunted by a serial killer in a rabbit costume.

Hear, smell, see, taste, and touch history at this immersive Civil War hospital.

Priceless space junk on display in front of a local Dairy Queen.