A spooky defunct railroad tunnel now part of a sprawling trail.

This elaborate towering structure was once famed for its revolutionary height.

Yo, Adrian!

This charming colonial alleyway is one of the oldest continuously used residential streets in the U.S.

Tour the dark and beloved poet's former cobwebbed basement, which may have inspired "The Black Cat."

A layered tribute to the work of mosaicist Isaiah Zagar.

America's most famous museum of medical oddities is home to the remains of Albert Einstein's brain.

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

The humble beginnings of the man known for his lavish "champagne" music.

The world's largest Holstein cow.

A true roadside icon standing on the same plains that the herds once roamed.

What is it about mushrooms that makes people wish they lived inside of them?

Climb a steep hill in 90 seconds on the second-oldest urban subway in the world.

Legend says if you stick your thumb in the hole and it gets wet your wish will be granted.

A marvel of Byzantine engineering under the streets of Istanbul.

For almost a century, this East Village newsstand has served egg creams to beats, hippies, punks, and everything in between.

A massive art collective tries a new take on Brooklyn's DIY music scene—by making it fully legal.

A graffiti Mecca welcoming artists from around the world.

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

A DIY art gallery/music venue/lecture hall dedicated to video game culture.

This former water source for the City of Brooklyn is now a thriving natural wetland.

An eerie diorama that captures the majestic nature of a few prehistoric-looking beasts.

This taxidermy scene brings the struggle for survival in the Indian jungle to a quiet corner of a Manhattan museum.

This poignant display is now a memorial to these regionally extinct species.