Italy is located in Southern Europe, and including the islands, Italy has a coastline and border of 7,600 kilometres (4,722 miles) on the Adriatic,Ionian,Tyrrhenian seas, and borders shared with France, Austria, Slovenia and Switzerland. This geographical closeness certainly touched the Italian cuisine as well. Modern Italian cuisine has developed through centuries of social and political changes, with roots as far back as the 4th century BC. Significant changes occurred with the discovery of the New World with the introduction of items such as potatoes, tomatoes, bell peppers and maize. The Mediterranean diet forms the basis of Italian cuisine, rich in pasta, fish, fruits and vegetables and characterised by its extreme simplicity and variety, with many dishes having only four to eight ingredients. A key factor in the success of Italian cuisine is its heavy reliance on traditional products; Italy has the most traditional specialities protected under EU law.