A building that survived WWII, possibly on the virtue of its name alone.

The bridge is a secret gallery of discarded gum that has been transformed into miniature masterpieces.

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

The gorgeous library at Trinity College is home to remarkable treasures of Irish identity.

The comedy and tragedy of Oscar Wilde is preserved in a Dublin park, captured in a sculpture of colorful stone.

The house where the writer spent his formative years.

The 19th-century pharmacy (now a used bookstore) was featured in James Joyce’s "Ulysses," and has changed very little to this day.

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

The modern birthplace of Irish freedom.

This statue celebrating everyday life in Dublin has a few unsavory nicknames.

A labyrinth hides in plain sight at each of the city's 270 Tube stations.

The anatomical-pathological collection of a man who changed surgery.

In the days before house numbers, these colorful signs held clues about various buildings' purposes.

Amsterdam's former hotspot for public executions and dissections.

This 22-floor tower's Skydeck offers panoramic views of Amsterdam.

Three connected pink triangles memorialize persecuted gays and lesbians throughout history.

Established in 1638 to battle the Black Death, Hortus Botanicus Amsterdam is a treasure trove of rare flora.

This city square is home to Amsterdam's oldest church and a statue honoring Dutch sex workers.

A Dutch passageway's artistic, aquatic-themed makeover pays tribute to the capital city's famed waterways.

The attic of a four-century-old canal house hides a clandestine church.

This enormous "cloth of the conquest" depicts the Norman invasion of England in mind-blowing detail.

Despite centuries of architectural innovation, this French castle is being built like it's the 13th century.

This stunning French estate was so lavish that it landed its original owner in jail for the rest of his life.

This 1,300 year old monastery built atop a single rock was once only accessible depending on the whims of the tide.