Koufonisi (Greek: Κουφονήσι, known as Leuce in antiquity) is an uninhabited Greek islet, located 3 nautical miles south of cape Goudero on the coast of Lasithi, eastern Crete, in the Libyan Sea. The island is roughly 6 kilometres (4 miles) long and 5.5 kilometres (3.4 miles) across. It has an entire surface area of 5.25 square kilometres (2.03 sq mi).