This Wall Street bar was once a hub of revolutionary activity where Washington famously bid farewell to his troops.

Mysterious 500-year-old tapestries depict a unicorn hunt.

Whisper secrets in a busy station only to be heard on the other side of this acoustic arch.

Read a book next to a Midtown waterfall.

Elevated freight railway turned wildly successful urban park.

A muscular Art Deco monument represents the struggle between regulators and unbridled markets.

An overlooked memorial honoring the local Washington residents who died in World War I.

Go take a picture with the inventor of the daguerreotype photographic process.

A much-maligned monument to teetotalism.

During the Industrial Revolution this “Temple of Invention” was full of intricate miniature machines and gadgets.

One of the dwarven trees dates back to 1625 and survived the Hiroshima bombing.

This palatial botanical garden is home to one of the largest pipe organs ever installed in a private residence, and a piece of Wood's cycad.

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

A tour de force of a fountain, memorializing a man who loved fountains more than anything else.

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

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

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

The highest point in Delaware is located under a trailer so this marker across the street will have to do.

The oldest surviving botanic garden in the United States.