A perfect circle of twenty-four mysterious holes dates back to prehistoric time.

This hunter-gatherer architecture is believed to be the oldest religious complex known.

Natural catch-basin rocks covered in thousands of drawings spanning many millennia.

The clock that sets them all.

The longest living non-clonal organisms on Earth.

Step into the cool deep past and unknown future of who begat who.

Native Americans built this circle of stones, which was used to predict astronomical events.

Potential high level nuclear waste storage site for the next 10,000 years and beyond.

The closest thing to Mars on Earth.

A small museum filled with over 1,000 clocks, and one particular clock calibrated to run until the year 9999.

A mysterious monument meant to be a guide into "an Age of Reason" was destroyed after an apparent bombing.

Home to Hollywood history and a very special salt crystal.

The world's first and only natural nuclear reactor.

Constantly maintained, this organ is playing a six-century long composition by John Cage.

Hidden behind Lincoln's head is a 70-foot-long chamber containing enamel plates documenting American history, sealed in a teakwood box in a titanium vault.

One thousand trees were planted in Norway to be used to print books a century from now.

Cold storage for agricultural biodiversity.

A musical composition 1000 years in length plays at the Trinity Buoy Wharf in London.

The world's first time capsule lies behind a welded steel door in Atlanta.

Colorful umbrella-covered trees in Singapore's Little India look straight out of Dr. Seuss.

This community on a small Venetian island has taken to painting their houses in bright neon hues.

As can be expected from a centuries old church built in a canal city, the undercroft of this house of worship is beautifully flooded.

This Venice bookstore has resigned itself to constant flooding by keeping its books in bathtubs and boats.

Pilgrimage site for star-crossed lovers.