The writing studio of an American adventure author, built in the style of a medieval castle.

The bones of an old zoo crumbling in the shadow of a new one.

The only surviving prototype for Buckminster Fuller's house of the future.

One man's attempt to create an artistic wonder on a run-down block in Detroit.

A Beaux-Arts triumph rises from decades of decay to become the heart of a new innovation district

A subterranean world of tunnels links several buildings of this rare 19th-century asylum.

A popular place to pick up prehistoric coral fossils from the time when Michigan was an ocean.

The Beaux-Arts aquarium boasts a vast collection of saltwater and freshwater fish on an island in the Detroit River.

Island where motor vehicles are banned -- home to the only carless highway in the United States.

This sprawling bookstore spans four floors and has more than a million books in stock.

The remains of an abandoned dinosaur theme park litter the woods just off the highway.

Abandoned concert venue legendary for its rock counterculture.

The city is full of whimsical portals to another world.

Hell on Earth is actually a small town in Michigan where anyone can be mayor for a day.

This Detroit ruin was once a gothic bastion of its community, but now it stands as a haunting ruin.

Hundreds of secret cabinets built into the walls of legendary poisoner's private work room.

A chapel on a volcanic core, marking the end of a successful journey.

A medieval church with largest and oldest collection of Renaissance frescoes in France.

Since ancient times these picturesque springs have been providing bathers with healing waters.

Saintly bones pressed into a wax effigy of a Catholic superstar.

Museum in a swimming pool where the water still flows.

An ancient monastery, a locked room, and a mysterious book heist.

This structure atop a craggy cliff in one of the most beautiful parks in Paris boasts an unbeatable view.

The narrowest street in Paris.