Radical Bookstore and Community Space.

Venture into the past with an unlisted exhibit hall featuring extinct birds.

The Ryerss mansion in Burholme Park now houses a community library and a museum filled with a trove of oddities from around the world.

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

America's smallest national park site is the former residence of exiled Polish national hero Thaddeus Kosciuszko.

South Philadelphia is home to Keith Haring's only surviving in situ collaborative public mural.

This little-known collection holds everything from "Dracula" notes, to the manuscript of "Ulysses," to the forged works of Shakespeare.

Philadelphia boasts one of the best — and most often overlooked — traditional Japanese gardens in North America.

A layered tribute to the work of mosaicist Isaiah Zagar.

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

A tribute to the 20th-century ball that cast a spotlight on Mexico’s LGBTQ community.

This stunning and ethereal mural symbolizes the beauty, unity, and diversity of humankind.

This clock was gifted to Mexico as a show of gratitude for its long history of welcoming Arab migrants.

Underneath the historic center of Mexico City, the remains of a temple dedicated to the Aztec god of the wind.

Its exhibits are dedicated to educating the public about state terrorism in Mexico.

This tiny, tucked-away eatery reflects the history of Mexico's Lebanese immigrants.

A small pack of an ancient, hairless breed of dog once believed to guide souls through the underworld lives on its grounds.

This once-abandoned mansion is now a dreamy event space.

This French cemetery houses some of the most exquisite examples of funerary art in Mexico City.

This Aztec structure remained hidden until the demolition of a supermarket exposed the lost temple.

An extravagant 18th-century fountain built with bits of broken ceramic.

The unique collection of gifts includes braids of human hair, a spoon, and a Virgin made of bread.

This ancient jade mask depicting the Zapotec bat god was found in the ruins of the pyramids of Monte Alban.

The ruins of an ancient temple to the Aztec wind god discovered in the middle of a metro station.