The only National Monument ever to go missing for nearly 50 years then resurface in a dump.

The hidden offices underneath Memorial Bridge have been locked up since 1976.

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

The beloved statue at the National Academy of Sciences is oh so inviting to sit on.

The first purpose-built art gallery in the United States is once again open as a center of craft arts.

The bank that helped fund the Mexican-American War and the purchase of Alaska met its downfall after helping Augusto Pinochet launder money.

An unassuming, powerful monument north of the U.S. Capitol bears witness to the resilience of Japanese Americans during a time of grave injustice.

The "lovely red Vega" of the legendary record-settling pilot.

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

A much-maligned monument to teetotalism.

The oldest surviving bridge in New York City, which reopened to pedestrians in 2015.

A crumbling hospital from the 1850s on Roosevelt Island.

Lie in a hammock where George Washington stood.

This opera house along the banks of the Connecticut River has two Tony Awards to its credit but it’s never staged a single opera.

The Connecticut village named for its subterranean thunder.

This museum holds a fully-functional replica of the "Turtle," the first American submarine ever built.

Quirky castle designed by the American actor best known for portraying Sherlock Holmes on stage.

A Civil War Museum with some notable medical antiques.

This Maryland farm is known for its amazing corn mazes and its 30-foot junkbots.