Under a glass sidewalk lie the remains of some of Manhattan's oldest buildings.

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

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

You can take a class, browse the library, or visit the lavish lair of an international men's humor society.

At Chicago's revered Field Museum, visitors are invited to learn about and literally explore DNA.

The site of the first couple's first kiss is commemorated by the most adorable presidential monument ever.

A Bibliophile's Dream.

Come for the pastrami, stay for the million-dollar art.

The phone booths of New York City have all but disappeared, but their remains were once found in this "graveyard," sadly now removed as well.

A huge resale shop for the cast-offs of the film & television industry.

An easy to overlook storefront hides some of the most authentic and regionally diverse Chinese food in New York.

A legendary speakeasy bookstore returns from the brink.

A temple belonging to the largest Buddhist order in South Korea nestled in the middle of New York City.

The competition: breathe deeply as long as you can.

Built just after the American Revolution, the oldest row house in New York City still stands in Chinatown.

This Queens beer hall preserves a German culture and language that is all but lost.

Once a month, an Indonesian feast appears inside an Elmhurst church hall.

A prized globe signed by Amelia Earhart and Charles Lindbergh sits in the Brooklyn office of the American Geographical Society.

Deliciousness abounds at a Guatemalan restaurant masquerading as a pizzeria.

A B.Y.O.B. Mexican cantina lives inside one of the last tortilla factories in Brooklyn.

Historical figures from New York City's Catholic community reside in Midtown.

An annual extravaganza of Broadway theater memorabilia.

The rough and tumble president's childhood home displays the shirt he was once shot in and the speech that saved him.

Avoid gangster interaction while window-shopping.