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

The final resting place of the author who gave us the Little Mermaid, the Ugly Duckling, and many more beloved fairy tales.

Pre-Nazi swastikas adorn the sculpted pachyderms flanking this brewhouse portal.

An ultra-modern diversity park in Denmark has turned an entire city block electric pink.

An Irish peat mine has become a stunning sculpture park.

An 1814 castle that hosts an exhibit of "explorabilia".

A hidden tunnel of bones in one of Malta's oldest churches.

This spectacular dome managed to survive after being bombed in World War II, in an event known as the "Miracle of Mosta."

The remains of a 1st-century aristocratic Roman town house featuring beautiful well-preserved mosaics.

These lesser-known Maltese catacombs date back over 1,700 years.

A centuries-old forgotten underworld lies beneath Malta.

Dynastic Home of the De Piro Family.

Ancient mysterious ruts carved in the bedrock.

The medieval home is still engraved with the symbol of the profession, an eye flanked by two axes.

This unique building in the main square stands out among the city's typically Baroque architecture.

Overshadowed by other, more famous Maltese catacombs, this ancient burial chamber has one of the best examples of a ritual agape table.

In the sleepy town of Gozo exists a reproduction of the entire town of Bethlehem.

This subterranean necropolis holds three floors of antler-dug grave caves.

Burial grounds for more than 1,000 bodies deep under the modern town of Rabat.

An abandoned set from the 1980 film "Popeye," claimed and repurposed as a theme park by creative locals.

Hanging within this medieval church are the bones of a beast allegedly slain by a fourth-century saint.

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

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

A sinister pyramid in the Frari contains the heart of the famous neoclassical sculptor.