The prototype for all Nazi concentration camps.

The footprint of a frustrated devil in Munich's Cathedral.

The patron saint of spinsters grasps a container of dried blood.

The world's tallest church tower reveals a spectacular view to anyone up to the task of climbing the daunting staircase.

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

The last remaining relic of San Francisco's glittering 1915 Panama Pacific Exposition.

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

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

Daily jousts and dancing barrel makers in Munich's mechanical clock.

The history of radiation is on safe display at the foot of a radiation science laboratory.

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

San Francisco's newly reopened hands-on science museum.

Great place to have a drink and a bite to eat in an atmosphere laden with New York's Bohemian past.

New York City's smallest piece of private property.

Elevated freight railway turned wildly successful urban park.

Named the fifth most beautiful building in America in 1885, this former courthouse boasts the best view in the Village.

The oldest operating apothecary in the US has treated everyone from Thomas Edison to Mark Twain.

Phil Mortillaro uses keys to bring art back to the Village.

Cryptic messages embedded in the New York City sidewalk.

The former hotel where Tesla invented the radio.

This iconic Parisian bookstore doubles as the "Tumbleweed Hotel" for traveling writers.

An artist's cute bronze subway sculptures belie his violent artistic past.

Cold war icon and onetime "hole" in the iron curtain.

The most visited, and possibly most controversial, museum in Germany.