An abandoned cemetery lies in ruins as the surrounding forest swallows it whole.

Dr Barnes' $25 billion private collection of art and arboretum.

World's first "penitentiary," meant to be humane, drove men insane.

The taxidermied remains of Charles Dickens' pet raven, which helped inspire one of Edgar Allan Poe's most famous poems.

The oldest surviving botanic garden in the United States.

This simple Manhattan salt house is artfully shaped... well, like a giant granule of salt.

An annual extravaganza of Broadway theater memorabilia.

The former home of the reclusive "Weird Wendels" who dominated New York real estate a century before Donald Trump.

Peek through the gates at this oasis from the city, full of Old English charm.

This small New York museum celebrates the mountainous artwork of a Russian mystic.

A Gothic-style abode built to accommodate the church's three resident peacocks.

The studio of influential composer Charles Ives is perfectly reconstructed, hidden in the back of the American Academy of Arts and Letters.

A memorial marks the library lobby where Langston Hughes' ashes are buried.

This Manhattan museum houses one of the largest collections of Spanish art and manuscripts outside of Spain.

Visit the monolithic tomb of America's most famous general.

One of the only single-person private gravesites in New York City.

This 1,300 year old monastery built atop a single rock was once only accessible depending on the whims of the tide.

Ancient catacombs form the foundation for this Rococo orgy of a church.

Stone Age solar temple is aligned with the sun on each equinox and solstice.

A pre-Columbian ceremonial and astronomical site built by the Taino Indians.

Rare collection of medieval books under lock and key.

Church featuring "high Victorian gothic" architecture.

The mummified heart of a saint lives on in this church—after a brief hiatus when it was stolen.

Oldest existing church in New York and the inspiration for Washington Irving's "The Legend of Sleepy Hollow."