A well-preserved network of cavernous tunnels have spent silent centuries removing Toronto's waste.

It celebrates a very stinky task and salutes London's fatberg-vanquishing team.

It's gunky, it's gross, and it's been freed from the sewer and put on display.

Theme park featuring miniature replicas of European monuments.

Cozy basement bar sports an inventory of over 2,000 beers.

Each spring, a dreamlike carpet of bluebells overtakes the forest floor.

Climb inside an iron crystal magnified 165 billion times its normal size.

Two geological phenomena in one precarious locale: a towering stone window, and a deep blue void.

These temples are among the oldest free-standing stone buildings in the world.

Dynastic Home of the De Piro Family.

This 50-foot-deep sinkhole created in the 14th century is home to rare plants and fungi.

Ancient mysterious ruts carved in the bedrock.

The ruins of a megalithic monument sit right in the garden of a luxurious Maltese resort.

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

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

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

The eclectic seaside sanctuary caters to a rather fowl crowd.

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

The Jesus tree of Malta bears a striking resemblance to Christ on the cross.

The floor of this spectacular Baroque sanctuary is covered in memento mori.

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.

This Stone Age solar temple aligns with the sun on each equinox and solstice.

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