The only theatre in the world constructed specifically for sound movement.

A huge musical instrument played by the ocean.

Neither Spanish settlers nor anyone since has been able to tell who built these strange California rock walls.

A Roman-inspired temple once controlled half of San Francisco's waters.

The old Niles Canyon Aqueduct in the San Francisco Bay Area is a bemusing and secret trail through nature for wayward travelers.

These remote Florida islands have a history of sea turtles and sunken treasures, and one of the world's largest coastal brick fortresses.

Hidden beneath the streets of London is a secret subway that only carried mail.

One man has carved a number of natural New Mexico caves into psychedelic sandstone temples.

A pier that used to act as a busy ferry dock is now a decaying favorite of local fisherman and urban artists.

A strange house built only at night, with rumored mystic inspiration.