Heraklion is the capital and largest city of Crete and the largest port of the island. Main economic sectors of the city are tourism, agriculture and trade. It offers industrial area 4 km southeast of the center. Heraklion also has one of the busiest airports (airport "Nikos Kazantzakis"). Heraklion is close to palace of Knossos and in the period of the Minoan civilization had the largest concentration of population in Crete. It is also the fourth largest city in Greece and Heraklion airport is also known as Nikos Kazantzakis International Airport, having been named after the famous writer of Crete.