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

A classically inspired temple in Redwood City.

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.

This Dresden church was purposely rebuilt Protestant after being demolished in World War II.

The largest treasure hoard in Europe is contained in a castle that was bombed out during World War II.

Silent memorial, using bone conduction to take people back to the Dresden Bombing of 1945.

When the rain falls, this drain system turns into a musical instrument.

A trio of giant wooden megaphones turn up nature's volume in this Estonian forest.

A musical instrument played by the sea.

A huge musical instrument played by the ocean.

This sculpture is an instrument played by the swell of the seas.

At 135 years old and counting, this historic print shop is heaven for poster nerds and music buffs.

Somewhere between an art studio and a print shop, this artists storefront is a house of worship devoted to type.

This once-palatial plantation may have been the site where a draft of the Declaration of Independence was written.

America's smallest town is run by its single citizen/mayor/librarian/bartender.

For 20 years, this whale skeleton has been slowly dripping oil on the floor of the museum where it hangs.

Within this lovely Richmond cemetery lie the remains of famous Virginians and some of Edgar Allan Poe's most beloved family and friends.

Thanks to modern navigational tools we now know that the true prime meridian runs through a park next door.

This huge concrete map of Scotland was built as a thank you gift from a Polish soldier.

A church that bred legends, and served as an inspiration for the Da Vinci Code.

This Scottish manor house is a lush relic from the life of a literary great.

One of the U.S. Forest Service's only mansions is outfitted with a dinner table for floating food.

This stunning French estate was so lavish that it landed its original owner in jail for the rest of his life.