Ride the subways of yesteryear.

The smaller of the three towers of San Marino is a former prison inaccessible from the ground level.

Where members of the Crossbow Corps of San Marino demonstrate their skills.

A guitar mounted on a wall in Temple Bar honors the Irish musician.

One of Ireland's most infamous prisons for rebels including men, women and children.

Dedicated to one of the darkest moments in Irish history, this memorial has faced its fair share of backlash.

An enormous, inside-out glass globe built in 1935.

100 massive sculptures in the Hudson River Valley.

A hugely vast Irish landscape of barren rock that stretches for miles.

While many places make the claim, the Library of Congress says this restaurant is the birthplace of the hamburger.

This stone gatehouse was once the entrance to a historic mountain resort, and it had a cameo in a cheesy cult horror movie.

The oldest continuously inhabited street in America.

Why have you never heard of the second most popular tourist site in New York?

Discovered by cows, these upstate New York show caves are presented with a healthy dose of psychedelic folk art.

A collaborative art project that transformed a neighborhood in NYC's Queens.

These whimsical works of art tell the story of the city's past and present.

The world's only international cryptozoology museum is host to an unrivaled collection of mysterious objects.

This anonymous businessman sculpted in bronze became an enduring memorial after 9/11, and had been mistaken by rescue workers for a survivor in the rubble.

How a century-old glass factory in Queens became a concert venue and arts center.

A former poultry store that looks like a giant duck and is one of the "seven wonders" of Long Island.

This outdoor gallery of sculptures along the East River was once a landfill.

Three acres of mythology-inspired sculptures are visible from the highway.

A living antique aviation museum in the historic town of Red Hook, New York.

"Gnome Chomsky" was once the largest gnome in the world, but is now simply tall for his kind.