A monument marks the beginning of the longest north-south road in the United States.

A small park commemorates the departure of the first-ever successful transatlantic balloon voyage.

This uninhabited island in Maine is home to various works of art left by visitors over the years.

A charming museum of natural history featuring dioramas and exhibits made entirely by college students.

The first handmade canoe built by members of the Passamaquoddy in over a century.

This massive solar system model is sprawled out across Maine's suburban wilderness.

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

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

A museum dedicated to the tragedy of Bloody Sunday.

The ruins of this medieval castle in Northern Ireland have inspired artists from C.S. Lewis to Led Zeppelin.

Northern Ireland's Brobdingnagian stepping stones.

This short bridge is the only thing connecting a tiny Irish island to the mainland.

The inscribed stone at Kilnasaggart is a remnant from nearly a millennium ago.

The ruins of a medieval monastery named after a type of tree.

This 14th century tower house was once the home of Irish poet W.B. Yeats.

Petrified footprints of one of the very first vertebrates to walk on land.

An ancient holy well said to be used by the patron saint of sailors and travelers, lost in the boggy west of Valentia Island.

A collection of housewares from recent Irish history adjoined by a tower from ancient Irish history.

Huge standing stones mark a site of megalithic mystery.

This European portal tomb has a capstone that weighs around 150 tons.

Ancient Bronze Age rampart that was used into the middle ages.

This Bronze Age tomb is the centerpiece of a clearing within a beautiful Irish forest.

This 5,300-year-old tomb with mysterious carvings crowns an Irish mountain.

This ancient Irish landscape boasts hundreds of legendary ruins.