This beautiful building in the heart of Manhattan's Financial District was empty for decades.

A massive underwater sinkhole made famous by Jacques Cousteau.

London's creepiest cemetery was once the site of dueling magicians and mobs of stake-carrying vampire hunters.

An emerald-green grotto just a short trip from Austin.

The intricate stonework of Machu Picchu serves as a testament to Incan engineers.

Relics of the 1894 Midwinter Exposition continue to delight visitors today.

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 most confusing clock in New York.

The second-largest cave chamber in the world was discovered in 1898 by a 16-year-old and a friend known as "Pothead."

The last moments of the ill-fated Pompeiians, frozen forever in plaster.

Whisper secrets in a busy station only to be heard on the other side of this acoustic arch.

Hear the quietest sound from across the dome.

Giant, natural amphitheaters made of delicate geological formations called "hoodoos."

The Denver airport is guarded by a 32-foot-tall sculpture of a demonic horse.

The seawater playground of gilded-era San Francisco burned to the ground in 1966.

Home to items never before seen by the public.

The site of the climactic scene from the classic horror film is now a historic landmark.

Breathtaking and huge 430 year old maps of Italy.

The second oldest continuously operating bar in Louisiana.

A marvel of Byzantine engineering under the streets of Istanbul.

A beautiful geyser under environmental threat.

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

The American Revolution was galvanized into serious action due to the tragic clash with British soldiers that occurred at this location.

Home to the largest urban bat colony in North America, estimated at 1.5 million bats.