The city of Avellino in Campania takes its name from the product for which it is celebrated, the hazelnut. The hazelnut tree comes from Turkey, but has been successfully adapted to grow in various part of Italy. More than half of the 100,000 tonnes produced each year come from Campania. The rest comes from Lazio, Piedmont and Sicily, where the nuts are particularly good. The variety called Tonda Gentile delle Langhe grows in the same area as the white truffle and it is said that the truffles which grow beside hazelnut trees are the best. Other varieties include Mortarelle, Gentile Romana and Nostrale di Sicilia.