Crete is the largest and most populous of the Greek islands, the 88th largest island in the world and the fifth largest island in the Mediterranean Sea, after Sicily, Sardinia, Cyprus, and Corsica. Crete and a number of surrounding islands and islets constitute the region of Crete (Greek: Περιφέρεια Κρήτης), one of the 13 top-level administrative units of Greece. The capital and the largest city is Heraklion. As of 2011, the region had a population of 623,065. Crete forms a significant part of the economy and cultural heritage of Greece, while retaining its own local cultural traits (such as its own poetry and music). It was once the centre of the Minoan civilisation (c. 2700–1420 BC), which is the earliest known civilisation in Europe. The palace of Knossos lies in Crete.