This legendary city has been a tourist attraction for centuries.

A miniature Italianate fantasy village on the coast of Wales and the set of ITC classic "The Prisoner."

Bacteria and algae give the salty water its bubblegum hue.

The prototype for all Nazi concentration camps.

The world's oldest bookshop still in operation.

A labyrinth of ancient tunnels hidden below the city holds the ruins of 2,500 years of history.

This impressive collection of rare books on ancient mysticism inspired author Dan Brown.

An illuminated manuscript comprising the life's work of a lone monk, inexplicably decorated with a portrait of Satan himself.

Western Europe's only representation of a Roman goddess still in its original location sits in an unassuming park.

Below a historic English market town lies a secret underground city complete with kitchens, laundries, storerooms, and an underground lake.

A priceless collection of the Nation's cryptologic history.

Fascinating town where normal life interfaces with the occult.

The universally beloved children's television figure is interred on a high hilltop in one of western Pennsylvania's oldest cemeteries.

The hotel where Martin Luther King Jr. was shot is now a museum dedicated to his work.

Ancient paintings known as the "Sistine Chapel of Cave Art."

The bunker where Hitler took his own life is hidden under this deliberately ordinary parking lot.

A restored Pittsburgh house of God has been converted to a marvelous house of suds.

Go inside to really appreciate this 500-year-old technological masterpiece.

A Victorian Gothic masterpiece housing a world-class collection of rare books and manuscripts.

A submerged village appears when dam levels drop.

These tombs were built into the side of a mountain so that ancient angels could reach the dead.

This Prague museum collects brutalist relics and memories from the country's former Soviet rule.

A multimedia experience that chronicles the atrocities of racism.

These Pre-Columbian petroglyphs contain representations of birds, deer, hunters, and even some early Native flute players.