The Stari Grad Plain on the island of Hvar is an agricultural landscape that was set up by the ancient Greek colonists in the 4th century BC, and remains in use. The plain is generally still in its original form. The ancient layout has been preserved by careful maintenance of the stone walls over 24 centuries, along with the stone shelters (known locally as trims), and the water collection system. The same crops, mainly grapes and olives, are still grown in the fields, and the site is also a natural reserve.