Curious cave that stays a cool 56 degrees all year long.

A whimsical bridge adorned with decorative dragons.

A trough of 700 strange bronze faces runs through a narrow alley in Ljubljana's old town.

A miniature train-ride through Slovenia's largest cave system.

This one-time health resort was used by aristocrats around the world.

The "dragon babies" of southeastern Europe.

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

This community on a small Venetian island has taken to painting their houses in bright neon hues.

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

This irregularly shaped sea fortress has defended not one but three different sovereign states.

This endearingly discomfited urinating statue commemorates the sneaky pees had by us all.

A subterranean house of worship carved right out of the bedrock.

The Guardian of Tallinn.

This dizzying tower was built to better broadcast the 1980 Moscow Olympics.

Only a fragment of this 15th-century Dance of Death survives today.

The de facto symbol of Copenhagen is this bronze fairytale which cannot seem to keep its head for very long.

It is said that each of the white stones in the red facade of this medieval house represents the head of a murdered Swedish noble.

The world's largest model of our planetary system.

It houses the remains of a 17th-century version of the Titanic.

A grove of colossal man-made flowers built to collect the sun's rays.

Home to the largest urban bat colony in North America, estimated at 1.5 million bats.

One part antique store, one part curiosities hodge-podge.

Continuing the tradition of the dime museum in style.

The tech giant built three enormous glass orbs in Seattle so employees could work inside a rainforest greenhouse.