A 90-year-old underground water reservoir offers a more industrial kind of tranquility.

This whimsical group of statues is a favorite of children who love to climb all over Lewis Carroll's beloved characters.

This mosaic dedicated to John Lennon was tended for years by a Beatles super-fan.

Hidden in Central Park's Ramble is a troublesome cave buried just beneath the surface.

Curious crustaceans support an obelisk from ancient Egypt that now stands in modern-day Central Park.

New York City's only wildlife rehabilitation center treats more than 3,000 feathered and furry patients each year.

One of the last Jazz Age "Wonder Theaters" in New York City.

Indents in the pavement are all that remain from a grisly death machine in Paris.

A horde of stray cats rule in this secluded Parisian cemetery under a bridge.

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

The oldest stone house in Paris was built by its most famous alchemist.

France's most famous cemetery, with some of its most curious tombs.

This southwest-styled home in Santa Fe claims to be the oldest house in America thanks to an ancient bit of foundation.

This innocuous New Mexico storefront was once the secret jump-off spot for Manhattan Project scientists.

Wedding chapel's mysterious spiral staircase said to be miraculously constructed.

What was meant to be a temporary exhibit is now a permanent fixture at the St. Louis Zoo filled with beautiful birds.

This titanic oil company sign is a reminder of the Americana boom of the 1970s and also its commoditization.

The Old Courthouse takes visitors on a captivating trip through St. Louis' timeline.

Four glass boxes hover over 1,000 feet in the air to give visitors an unparalleled view of Chicago.

New York's unstoppable progress turned this cemetery into the smallest burial ground in the city.

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

The former sign of this immortal music venue is just that--undying.

A hidden "place of interment for gentlemen."

Walk over a 150 year old manhole.