Around 100,000 bodies are buried below the medieval headstones, many of which mark graves with multiple bodies stacked up to 12 deep.

Explore the largest pure gypsum deposit in the world, and go dune sledding while you're at it.

The most confusing clock in New York.

One of Antoni Gaudí's most classic buildings is well-known for its "dragon-back" design.

Breathtaking and huge 430 year old maps of Italy.

Relics of the 1894 Midwinter Exposition continue to delight visitors today.

Whisper secrets in a busy station only to be heard on the other side of this acoustic arch.

One of the Seven Wonders of the Modern World holds the world's tallest metal staircase.

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

One of the tallest buildings in Iceland, and perhaps, the most visually impressive.

A little sculpture with a large wardrobe.

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

This mosaic dedicated to John Lennon was tended for years by a Beatles super-fan.

Famously misunderstood wonder of the ancient world

The vast, legendary catacombs hold secrets much stranger than stacked bones.

Elevated freight railway turned wildly successful urban park.

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

The celebrated eyesore created by starry-eyed sweethearts.

A bit of retro transportation flair preserved in the world's largest department store.

A tropical paradise just a short trip from the opera house is filled with beautiful winged creatures.

1,001 carved statues of the Buddhist God of Mercy, each with a unique face.

The 10,000 Torii shrine.

The sound of swaying stalks in this stunning grove has been named a governmentally recognized sound.

These medieval skyscrapers dominate the skyline of this small Tuscan town.