Touching mementoes from those who didn't make it back from World War I still hang in one of New York's oldest bars.

The most confusing clock in New York.

This Fifth Avenue church has long been the favored worshiping place of Broadway actors and vaudeville performers.

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

Spinning silently in the lobby of an Art Deco masterwork is a massive vintage model of the Earth.

A very classy 1920s-era bar right in Grand Central Station.

A celebration of capitalism in Midtown.

A small peaceful park and waterfall tucked amid the urban grind of Midtown Manhattan.

The first and only carousel with a lineup entirely of insects.

Mysterious 500-year-old tapestries depict a unicorn hunt.

Home to the infamous "Typhoid Mary" and the worst loss of life in New York's history prior to September 11, 2001.

The New York hotel where tragic visionary Nikola Tesla spent his final hours, destitute and alone but for the pigeons.

A grand New York post office that is home to mailman Santas, scraps of postal history, and a pneumatic mail system.

A bit of retro transportation flair preserved in the world's largest department store.

Empty, but not abandoned, this cavernous Brooklyn loading dock was once considered the largest individual building in the world.

A UFO-shaped event building originally intended to be a science museum showcasing the future.

Sitting in the basement of a castle, the largest wine barrel in the world is bigger than most apartments.

These 20-foot jaw bones honor a time when the leviathan bones were a sign that whalers survived the hunt.

The gloomy ruins that inspired Bram Stoker to bring Dracula to life.

The "beautiful" equation predicting the movement of all electromagnetic particles is engraved in front of Newton's tomb.

The John Snow Memorial marks the epicenter of London's 1854 cholera epidemic.

One of England's most famous churches hides a pair of little known architectural treasures.

One of the few standing Roman lighthouses and a labyrinth of tunnels are a couple of the secrets at this historic castle.

The perfectly preserved underground rooms where Churchill plotted the war against Germany.