Porto is Portugal's second largest city and the capital of the Northern region.
Porto is a busy industrial and commercial centre. The city itself isn't very populous (about 300,000 inhabitants), but the Porto metropolitan area (Greater Porto) has some 2,500,000 inhabitants in a 50km radius, with cities like Gaia, Matosinhos, Maia, and Gondomar. The city was built along the hills overlooking the Douro river estuary, and its historical center was awarded World Heritage status by UNESCO in 1996. It has been continuously inhabited since at least the 4th Century, when the Romans referred to it as Portus Calle Porto has a semi-Mediterranean climate, although it's strongly affected by the Atlantic ocean, which makes it cooler than other cities with this climate. However, temperatures can rise as high as 40ºC in August during occasional heat waves. Winters are mild and humid, with occasional cold nights where temperatures can drop below 0ºC. Porto has always been a mercantile city, and this is evident in the style of the buildings lining the Avenida dos Aliados, the core of the downtown area. The center of town, unlike other major Portuguese cities, which tend towards the baroque, is granite and monumental. Residents of Porto are known as Tripeiros (tripe eaters) due to the fact that the city went without meat in order to provision the capital and the fleet that departed to Ceuta in 1415, had to subsist on tripe stew, still a speciality of the city.