In places like Dubai there are enough wealthy people to warrant such an outrageously expensive and labor-intensive process as creating an island. See the incredible photos of this astonishing engineering feat.
Dredging ships spray a specific type of sand (326 million cubic meters worth) onto one location in order to create the actual base of the island.
Afterwards, huge rocks are placed one by one around the island(s), creating a “barrier reef”.
Needless to say, these man-made islands don’t come cheap. Even the sand has to be specifically chosen to stand the test of time. Some types of sand are too dense and would sink, while others are too light and would slowly blow away over time.
These particular islands are made from sand that came from the coast of the Persian Gulf.