The mysterious wonder of an underground waterfall is illuminated by multicolored lights.

World's largest barrel containing an inn.

Sitting in the basement of a castle, the largest wine barrel in the world is bigger than most apartments.

It's good luck to be mocked by this monkey.

The last bastion of Roman presence north of the Alps looms over a German town.

Eight rare Corvettes are swallowed up by a sinkhole in Kentucky's National Corvette Museum.

The world's longest known cave system.

A pedestrian island in the middle of world-famous Times Square emits a strange (and purposeful) humming noise.

It may look like no more than a full-scale model, but every part of this full Space Shuttle stack had a working role in aviation history.

A propulsion engine testbed that paved the way for the Space Shuttle launch sits without recognition at this rocket center.

A daily replay of the experiment that proved the rotation of the Earth.

These 20-foot sculptures will help guide you from the local train station to the local sculpture garden.

A unique sculpture park that specializes in the huge and bizarre.

This Delaware River bridge is emblazoned with a catty slogan from a more prosperous time.

This giant disembodied horse head seems to balance impossibly on its nose.