Mysterious rocks that ring musically when struck.

This fort down the Potomac from Washington, D.C. was once the only defensive fort protecting the capital.

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

The fifth-longest suspension bridge the world, connecting one Michigan peninsula to another.

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

World's largest Christmas store.

The former home of the Nobel Prize-winning American writer is now home to dozens of six-toed cats.

Send a postcard while vacationing with Satan.

A wall of chewing gum moonlights as collective art.

Upside-down trees serve as natural flower pots in this hanging garden of Alaska.

A historic freight system that found the true gold rush is in tourism.

Museum of Fijian history, including its former tradition of cannibalism.

This palatial botanical garden is home to one of the largest pipe organs ever installed in a private residence, and a piece of Wood's cycad.

This jail which was in service for over a century is now open for curious visitors.

A unusual sanctuary for abused and exotic animals in South Jersey.