The fishing boats that moor in this small lagoon enter and leave through a tunnel to the sea.

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

Stone Age solar temple is aligned with the sun on each equinox and solstice.

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

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

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

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

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

Over the centuries, this island paradise has done it all, from providing monks with ecclesiastical respite to sheltering an exiled Leon Trotsky.

A marvel of Byzantine engineering under the streets of Istanbul.

This Italian foot path winds through the mountains via 52 individual tunnels.

An open-air museum in a mountain valley features works designed to blend in with—and disintegrate back into—their natural surroundings.

This military mausoleum captures the solemn grandeur that most memorials only aspire to.

Beneath Kraków Old Town's main square lies a hologram-filled medieval market vampire graveyard wonderland.

Built in 1870 at the bridge that connected Buda and Pest, this spectacular incline railway was almost lost forever during World War II.

The geographical center of Budapest is marked with a 10-foot-tall stylized zero.

Steadily reminding Czechia of its past.

A mocking tribute to the past and modern leadership of Prague.

The deepest sinkhole in Central Europe comes with a grisly tale and an unusual nickname: “The Stepmother Abyss.”

Looming communist pillar with a Czech twist.

This automated sculpture of two men peeing will spell out text messages with their micturition.

An effigy of a trapped paratrooper dangles from a Normandy church to commemorate one remarkable D-Day event.

The tunnel's elegant proportions keep you snug with no claustrophobia freak-out.

Europe's second largest ossuary wasn't discovered until 2001.