The unbelievably opulent home built for an infamous newspaperman.

A majestic mansion designed in Mughalai style, complete with a turquoise onion dome.

The world's largest collection of materials relating to lesbian history is housed in a Brooklyn townhouse.

Leaf through over 30,000 artists' sketchbooks in what may be the world's largest collection of doodles

The one-stop shop for all of your superhero (or evil arch-nemesis) needs.

A Collegiate Gothic quadrangle that surrounds an 18th century secondary school whose financing came from the likes of Alexander Hamilton and Aaron Burr, among others.

A modern addition to the Greenpoint skyline.

This futuristic airport terminal was abandoned for decades before reopening as a hotel—with a vintage plane of its own parked out back.

Piano-making empire filled with 200-year-old steam machines still churning out 1,000 instruments a year.

This outpost of America's most popular fast-food restaurant is housed inside a palatial mansion.

Offbeat arts organization that hosts exhibitions, events, and explorations.

Nondescript elevator doors open to reveal a stunning, surreal world.

This Orthodox Church's exterior is rather unorthodox.

The preserved house of a jazz legend still echoes with his music.

This enormous Hindu temple in Queens serves incredible dosas in its basement canteen.

The remnants of two World's Fairs are here, complete with a 12-story globe, a mini-Manhattan, and a UFO-shaped pavilion.

The crown jewel of the Queens Museum is a nearly 10,000-square-foot architectural model of the city originally built for the 1964 World's Fair.

Northern Ireland's church-turned-skate park.

An abandoned bait shop with a front lot filled with storage boxes.

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

Historic Greenpoint theater, turned roller disco, now housing a chain pharmacy store.

Check out the underground party scene at the "Burning Man of Brooklyn."

This ancient oak tree plays matchmaker for singles willing to branch out from the usual dating scene.

The bartenders at this crime-fighting theme cafe are actual private detectives by day.