The world's first clock to use set theory as a measure of time required the invention of a new light bulb just to maintain its obtuse measurements.

These brass bunnies honor the rabbits that dominated the no-man's-land around the Berlin Wall.

Someone loved this song enough to carve all of its lyrics onto a tree trunk in a Berlin park.

A tree-like building perches on its trunk in the Steglitz neighborhood of Berlin.

Residents of Berlin take their coffee and cake in one of the city’s most restful spaces: a cemetery.

Started as a kitchen garden, now the second largest botanical garden in the world.

Explore Dublin's laneways full of diverse street art and graffiti.

The house where the writer spent his formative years.

This Moorish fortress has guarded Málaga from the slopes of Gibralfaro hill for nearly a thousand years.

A cynical face-off exposing the cost of war.

An incredible natural formation along the Wild Atlantic Way.

The (fictional) address of Sweeney Todd's bloody barbershop.

A monument to a beloved aquatic folk hero in the Irish town of Dingle.

A hiking/biking/exploring trail that winds across over 140 miles of Rwandan shoreline.

Outside an Irish football stadium are murals commemorating history and local heroes.

After it was swallowed by a Georgian mansion, this medieval castle remained forgotten for centuries.

These gigantic skeletons tower over visitors and provide insight into the creatures that once ruled over Ireland.

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

Dublin's most modern, visually spectacular bridge is modeled after Ireland's national emblem.

A devastating booze inferno poured through the streets, claiming several victims who drank it.

The graffiti that birthed modern algebra.

This colorful and fiery mural depicts the Irish folk story of the beloved hero Cuchulain.

A two-storey cabinet of wonders filled with the bizarre, the macabre, and the downright uncanny.

At night, this memorial illuminates a ghostly outline of a footbridge that connected two sections of the Warsaw Ghetto.