The Vatican's secret porn-festooned bathroom was painted in erotic murals by one of the greatest artists of the Renaissance.

Hidden beneath the famous St. Peter's Basilica is a veritable city of the dead that may hold the remains of St. Peter himself.

The original toys that inspired the beloved children's stories are on display at the New York Public Library.

Wall Street has a new heroine, a bronze statue of a small but fierce girl.

The oldest surviving bridge in New York City, which reopened to pedestrians in 2015.

A three-story copper skybridge connects two Manhattan buildings with Art Deco luxury.

A masterpiece of LGBT art has been restored in what may now be the most valuable restroom in America.

New York City's smallest piece of private property.

The "Seinfeld" diner.

Ride the subways of yesteryear.

This little museum is built on a theater that was once a wildly elaborate speakeasy.

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

This lower Manhattan bar is set up in an old bank vault that rests beneath a skyscraper that hides even more historic splendor.

The world’s oldest and biggest bookstore stocking only mystery, crime fiction, espionage, and thrillers.

Manhattan’s Battery Park has a whimsical carousel full of spinning, glowing fish.

Historic funicular railway, believed to be the shortest railroad in the world.

One man's homage to the sun continues to grow like a glass fractal.

America's most famous piece of self-built architecture.

Hidden in the hills of Hollywood, this secluded Oz-themed garden is dotted with dozens of thrones.

It should come as no surprise that the best view of the Hollywood sign is from Batman's lair.

An open-air "garden" of mural art that changes weekly.

On the wall of this medieval walkway, a symbol of the Spanish Inquisition.

One of Antoni Gaudí’s earliest buildings, built between 1886 and 1890 for the industrialist Eusebi Güell.

One of the most photographed buildings in a city known for its Modernista architecture is an abandoned squat.