Once the tallest building in the world and the site of “the highest dinner ever held in New York” this building now holds the most expensive penthouse in the city.

One of only two commuter aerial tramways in the United States.

This cemetery has graves dating back to the 17th century, including the city's oldest carved tombstone and an ominous cryptogram.

A pedestrian island in the middle of world-famous Times Square emits a strange (and purposeful) humming noise.

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

Elevated freight railway turned wildly successful urban park.

Try not to get slimed in Tribeca.

This beautiful building in the heart of Manhattan's Financial District was empty for decades.

Once the future of underwater combat, this old sub is now open for visitors to muck around in.

Carved, egg-shaped stone with no explanation.

"the sweltering inhabitants of Charleston and New Orleans, of Madras and Bombay and Calcutta, drink at my well . . . The pure Walden water is mingled with the sacred water of the Ganges."

A former zoo turned public park, where visitors can hang out in the old animal cages.

America's oldest archaeological site or a muddled case of wishful thinking.

Former abode of notable poet, complete with literary references and stories of ghosts.

Mrs. Mallard and her brood are a beloved fixture in Boston Public Garden.

A beautifully eclectic mix of architectural styles.

How did a French journalist’s grave become the sexiest statue in the cemetery?

This bronze boar's snout has been rubbed to a golden sheen by visitors seeking good fortune.

This Dutch-styled residential building was originally a cocoa company's World's Fair showpiece.

Berthed at the Charlestown Navy Yard in Boston, "Old Ironsides" is the oldest commissioned warship still afloat.

This monument on Breed's Hill proves that one of the most famous battles of the Revolutionary War is misnamed.

Two thousand artifacts from around the world collected by one woman who loved to travel.

American revolutionaries and British soldiers alike are buried here in the fourth-ever cemetery in Boston.

The Boston square dedicated to the dark poet who was born nearby.