Sky ships, planes, and portraits left as unique tokens of hope and thankfulness.

This garden houses the remains of the ancient Greek port of Marseille.

This modern museum of Mediterranean culture is surrounded by a surreal concrete honeycomb.

These engineering masterpieces are a dominant feature of the Belfast skyline.

A museum marks and documents the site of the Titanic's launch.

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.

The atmospheric road was never meant to be so creepy.

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

This ancient Irish tower could easily have stood in for Rapunzel's prison.

The ruins of a sixth-century monastery sit on the banks of the River Shannon.

Construction of Barcelona's iconic (but controversial) church is expected to be completed in 2026—a century after the death of its architect.

An early 20th-century bullring converted into a modern shopping center.

The iconic boulevard is the perfect place to catch sight of a bicycling skeleton, a levitating Satan, or a chef with his head stuck in a pizza.

One of Antoni Gaudí’s earliest buildings, built between 1886 and 1890 for the industrialist Eusebi Güell.

The only museum with its curator—and her pets—buried inside.

Thousand-year-old Viking runes adorn an ancient Greek lion at the entrance to the Venetian Arsenal.

This Venice bookstore has resigned itself to constant flooding by keeping its books in bathtubs and boats.

Go inside to really appreciate this 500-year-old technological masterpiece.

Two stone columns flank the grand Venice square, but there were supposed to be three.

A twisted steel beam from the wreckage of the World Trade Center is the centerpiece of this memorial for those who died on September 11, 2001.

Built to repay the sins of the father, this church is home to one of the most valuable works of Western art.

The oldest botanical garden in the world that technically isn't the oldest.

The incorrupt tongue of the patron saint of lost things is venerated in this basilica.