A remarkably intact castle that once was the largest in Ireland.

A tiny microvalley etched into the side of Knocknarea Mountain hides another world.

Site of a former hidden treehouse in New Orleans.

A collection of oddities including Dr. Kevorkian's suicide device, the Thanatron.

This cathedral dedicated to Louis IX, sainted King of France, holds many secrets.

Taxidermied cartoon heads, unseen illustrations, and famous characters all reside in this small gallery space.

This unique shop is full of memento mori art, antique medical equipment, secret society paraphernalia, and historical relics.

This "second" cemetery represents New Orleans' attempt to keep cholera at bay.

This symbolic piece of New Orleans architecture is also home to a few ghastly stories.

This historic "City of the Dead" lies prominently in the center of New Orleans' famous Garden District.

The oldest cemetery in New Orleans, resting peacefully for over 200 years now.

This New Orleans tree is filled with hidden chimes that produce a carefully tuned melody.

A 200-year-old bar in the historic French Quarter refuses to give up its place in history, nor its role in securing ours.

The final resting place of New Orleans' most famous voodoo priestess.

A theme park that suffered massive flooding during Katrina was abandoned, and now proves irresistible to trespassing explorers.

This macabre shop, filled with art, oddities, and taxidermy is hidden in the heart of the French Quarter.

A museum and shop on Bourbon Street located in the former home of the second Voodoo Queen of New Orleans.

This fantastical and eclectic English garden takes its inspiration from Egypt, China, the occult and more.

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

This is the largest cemetery in Ireland and the first cemetery museum in the world.

The ruins of a medieval monastery named after a type of tree.

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

A stunning Victorian abbey and walled garden on a lakefront.

An 1814 castle that hosts an exhibit of "explorabilia".