The oldest operating Mississippi River–style steamboat still navigates the Ohio River.

The massive, original Colgate Clock is mounted on a defunct factory building that was once a prison.

Marine fossils from the Devonian period are exposed at this park.

This open air cathedral invites all faiths to worship under the only roof big enough to fit them all: the sky.

Four, 18-foot-tall badminton shuttlecocks lie scattered about the lawn of a Kansas City museum.

A magnificent church designed by world-renowned architect, Frank Lloyd Wright.

This otherworldly church spire reaches up toward the heavens.

A gem in the small Missouri town where Winston Churchill coined the term "Iron Curtain" and effectively began the Cold War.

400 million-year old limestone caverns nestled in the Ozarks served as shelter and a hideout for cultures throughout North American history.

What was once a presidential estate is now an exotic menagerie and home to the Budweiser Clydesdales.

Less a museum than a bizarre fantasy world created by artists and engineers.

One of the world's earliest skyscrapers.

The Old Courthouse takes visitors on a captivating trip through St. Louis' timeline.

Fresh wooden posts have been added to ancient holes to recreate a primitive henge clock.

Once one of the world's great cities, Cahokia was a place of religious worship, trade and mass human sacrifice before being mysteriously abandoned.

Iceland's tribute to its thankless civil servants.

This stunning concert hall has become a symbol of Iceland's national recovery.

One of the tallest buildings in Iceland, and perhaps, the most visually impressive.

Medicinal spa created from the mineral-rich runoff of a geothermal power plant

Climb right into the heart of this colorful Iceland volcano.

The picturesque birthplace of Icelandic democracy is drenched in the blood of its brutal past.

This eye-popping Icelandic crater lake is surrounded by red volcanic rock.

Inside this Icelandic greenhouse, geothermal energy keeps tomatoes warm and growing.

This valley of hot springs and boiling mud pots is home to the record-holding "Geysir," which originated the English word.