Gutted during the Liverpool Blitz, this architectural husk has been left destroyed in honor of the dead.

Though they've since been renamed, these two streets hint at Dublin's darker days.

The 19th-century pharmacy (now a used bookstore) was featured in James Joyce’s "Ulysses," and has changed very little to this day.

A nun spent 16 years painting the stunning Celtic mural that covers the interior of this WWI memorial.

More than 5,000 artifacts donated by the people of the city, plus a room entirely devoted to the band U2.

The enchanting archway is the only surviving portal into Dublin's lost medieval wall.

The oldest public library in Ireland.

Dublin's "Dead Zoo" serves as a window to Victorian museum design.

The mummified heart of a saint lives on in this church—after a brief hiatus when it was stolen.

This permanent collection of preserved bodies taken from Irish bogs is one of the leading authorities on such morbid mummies.

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

An Irish church where an 800-year-old mummy is reaching out of his coffin as if to shake hands.

The gorgeous library at Trinity College is home to remarkable treasures of Irish identity.

Amidst the bustling streets of Dublin, there is a hushed garden that is dedicated to "All those who gave their lives in the cause of Irish Freedom."

Read a book next to a Midtown waterfall.

A hip bar decorated with walls of golden skulls.

The feral felines of Roosevelt Island have a small army of allies and an abandoned hospital all to themselves.

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

A Pythagorean funhouse that tries, successfully, to prove that math is the coolest thing ever.

A miniature rainforest is growing inside of a Midtown Manhattan office building.

Amid the bustle and noise of the Financial District hides a secluded garden oasis above the city streets.

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

A treasure trove of artifacts, books, and artwork from the "golden age" of exploration.

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