An abandoned coal mine reached by a steep hike.

One day a year it is legal to jump off of this astoundingly tall bridge that spans an Appalachian gorge.

This miniature village stays behind in the Breuer Building, even as the museums around it come and go.

The oldest active church in Pennsylvania is also the second oldest Swedish Church in the United States.

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

The origin of this mechanical boy was a mystery until he revealed his maker by writing it in perfect cursive.

The first American department store, and home to the largest operating musical instrument in the world.

The sounds of the world's largest fully functioning pipe organ dazzle shoppers at a Philadelphia Macy's.

Golden and naked, the figure that was once the highest point in New York is all that remains of the second Madison Square Garden.

Huge masonic hall in Philadelphia with lavishly themed rooms.

Yo, Adrian!

This elaborate towering structure was once famed for its revolutionary height.

A daily replay of the experiment that proved the rotation of the Earth.

The artist and New York City icon lived, worked and died in this converted carriage house owned by another iconic artist, Andy Warhol.

"A hideous albatross in the Hudson River Valley."

One of the most scenic falls in Massachusetts has a history of death and grim legend.

Once considered the height of medical modernity, this structure is now the oldest remaining component of Roosevelt Hospital.

This translucent sculpture represents a quintessential component of New York City's skyline.

One of the last few places in Manhattan that employed a pneumatic systemic keeps it on display.

A beautiful collection of architectural ornaments rescued from demolished New York City buildings.

This enormous banquet-themed artwork honors over 1,000 notable women throughout history.

The home of one of America's most wealthy industrialists is now a historic site that remembers a more decadent time in the country's history.

You must take the A train... to the last active cemetery in Manhattan.

A plaque immortalizes the spot where the early American spy said his famous last words: "I only regret that I have but one life to lose for my country."