Northern Ireland's Brobdingnagian stepping stones.

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

A hugely vast Irish landscape of barren rock that stretches for miles.

This singular Irish dolmen is more Frank Lloyd Wright than upright stonehenge.

The ruins of an 800-year-old monastery boasts the tallest round tower in Ireland.

On the Spree bank, discover one of the last reminders of a symbolic wall that divided, and was torn down by the people.

One of the most popular megalithic sites in Ireland stands as a humbler version of Stonehenge.

This ancient Irish religious site is covered in ancient carvings, many of which have barely aged.

A magical and peaceful ruined Cistercian abbey in what is now southern Belgium.

A giant bug impaled on a 75-foot-tall needle.

Lavish royal estate punctuated with heated greenhouses.

Climb inside an iron crystal magnified 165 billion times its normal size.

A little sculpture with a large wardrobe.

Brussels' favorite peeing boy has a sister.

This water-tower-turned-high-end-apartment building was once the site of an early Nazi concentration camp.

The bunker where Hitler took his own life is hidden under this deliberately ordinary parking lot.

The site of the famous Nazi book burning campaign of 1933 remembers its "Night of Shame".

The ruins of this Dutch castle sit atop a labyrinth of once-secret tunnels and passageways, dating back over 900 years.