From buildings furred like seed pods, to massive funnels that capture rain, the structures of the Shanghai Expo - opening in May - are an homage to fantastical design. Each country's pavilion is weirder than the last.

International Expos date back to the 19th Century, when the cities hosting them would build incredible pavilions and buildings to impress the world with their industrial prowess. Many cities like London and San Francisco are still packed with leftover architectural wonders from World's Fairs (as they were also called) and Expos. Shanghai continues this tradition by creating one of the most memorable Expo landscapes in recent memory.

See even more of the weirdness via's Big Picture.

The "seed cathedral" in the UK pavilion is covered by 60,000 transparent acrylic rods that will move with the wind like a seed pod.

More of the seed cathedral

This enormous structure is designed to capture sunlight and rainwater for the green parts of the expo.

Testing the lights in the interior of the Chinese pavilion.

"Joy Street", part of the Dutch Pavilion

Luxemburger Pavilion

Spanish pavilion

Closer look at the materials being used in the Spanish pavilion. Looks recycled.

Polish pavilion

The South Korean pavilion looks like an inverted Rubik's Cube of some kind.