Friction between grains of sand cause a curious "singing" sound.

Three prestigious academic collections come together to create a world-class natural history museum.

Over 50 whirling pools left behind from the glacial age.

Site of a famous 19th-century transcendentalist utopian community, now abandoned.

The ruins of a Massachusetts prison farm can still be found crumbling the woods of a state park.

The American Revolution was galvanized into serious action due to the tragic clash with British soldiers that occurred at this location.

This miniature feudal castle was built on a whim to honor a US Navy pioneer.

The abandoned "Red Star Train Graveyard" is the final rusting place for precious artifacts of train history.

This quaint Hungarian railway system is operated exclusively by children between the ages of 10 and 14.

The final resting place for the remains of 143 Habsburg royalty.

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

Handsomely crafted representations of our round planet.

A spherical "micro-nation" in the heart of Vienna.

A patriotic medieval knight in driven-nail armor raised money for widows and orphans of WWI.

The housing complex served as an anti-fascist fortress during the Austrian Civil War.

More than a millennium's worth of municipal records preserve the political history of Austria.

This cave was once thought to be a hiding place for the devil.

The only university zoological museum in London houses extinct animals, bizarre natural history specimens, and a Micrarium of microscopic creatures.

A notorious punk house turned co-op.

An Irish cemetery filled with victims of political strife and violent conflict, including the grave of Bobby Sands.

Wallabies live naturally on this Irish island.

Catholics make up 84% of Ireland's population but this Dublin museum remembers the small but important Jewish community.

Amidst the bustling streets of Dublin, there is a hushed garden that is dedicated to "All those who gave their lives in the cause of Irish Freedom."

An enigmatic monument to the Irish revolutionary who plotted an uprising against British rule.