Engineers made the island by scooping sand from the seabed and shaping it into the palm-tree pattern. They used a special technique called 'rainbowing', where boats spray sand high in an arc, like a fountain, to drop it exactly where they want it. No concrete blocks underneath - the whole island is mostly sand.
Around the outside, a curved sea wall of huge rocks protects the palm shape from the waves. Each rock had to be lowered into place one at a time. Divers swam down to check that every single one was sitting properly on the seabed.
Today, the 'fronds' of the palm are lined with houses, each with its own piece of beach. The 'trunk' has shops and hotels. A monorail train carries people from the bottom of the trunk out to the very tip.
From space, the island is so big and so clearly palm-shaped that astronauts can see it from the International Space Station. It is one of the easiest human-made things on Earth to spot from orbit.