Lombardy is one of the twenty administrative regions of Italy, in the northwest of the country. Milan, Lombardy's capital, is the second-largest city of Italy and the largest metropolitan area in the country. Lombardy borders with Switzerland to the north and is bounded by Piedmont to the west, Trentino-Alto Adige and Veneto to the east and Emilia-Romagna to the south. Lombardy’s regions are: Bergamo, Brescia, Como, Cremona, Lecco, Lodi, Mantua, Milan, Monza, Pavia, Sondrio, Varese. Lombardy is the fourth region of Italy by surface, after Sicily, Piedmont and Sardinia, and has a relatively simple morphological structure. About 40% of the northern part is made by mountains while the remaining southern half of the region, which occupies more than 47% of the territory, is flat and extends in the central part of the Po Valley. The protected areas of parks and reserves, thanks also to the important action of WWF (WWF oasis), occupy about 7% of the regional area. In the region, there are numerous rivers, lakes, and water sources, which allow for an abundant availability of water. Among the main rivers and their tributaries are the Po, Ticino, Mincio, Adda, Brembo, Serio, and Oglio. The main Lombard lakes are, from west to east, Lake Maggiore or Verbano, Lake Lugano or Ceresio (50.5 km2, partly in Swiss territory), connected to Lake Maggiore by the short river Tresa, Lake Como or Lario (145.9 km2), Lake Iseo or Sebino (65.3 km2) and Lake Garda or Benaco (370 km2). However, only the lakes of Como and Iseo are entirely within the territory of Lombardy. The climate of the region is semi-continental, with harsh winters, often foggy, and hot and muggy summers. On the hills, the summers are less hot; on the shores of all the lakes of Lombardy, the local climate is significantly mitigated by the presence of the water masses of the pre-alpine lakes. The weather therefore turns warm in winter and not excessively hot in summer. Incredibly, the mild climate characterizing the banks of the great pre-alpine lakes allows the growth of even Mediterranean tree species, such as olive and lemon trees, as well as beautiful blooms of camellias, oleanders and holm oaks. It all makes the perfect ambiance for the numerous popular holiday resorts present in the area. Agriculture has very high productivity values; in fact, it supplies 10% of Italian production. It is a sector that has various specializations, among which stand out, in the lower area of the plain around Pavia, the wine grapes of Oltrepò Pavese and Valtellina, and rice in the Lomellina area. An economic role that is anything but modest is occupied by tourism, with over 11 million customers in hotels every year, not counting campsites and hostels. Lombardy has a rich and varied cultural heritage. The various examples of artistic and cultural heritage that enrich the cities and towns of the region can be found both in its museums and in its churches. This heritage dates back to prehistoric times up to the present day, through the Roman period and the Renaissance. The main tourist destinations of the region include the historical, cultural and artistic cities of Milan, Bergamo, Brescia, Pavia, Mantua and also many popular holiday resorts on the pre-alpine lakes such as Desenzano, Sirmione and Gardone on Lake Garda, Bellagio and Menaggio on Lake Como, Lovere on Lake Iseo, Lake Maggiore etc. The main tourist destinations in the Alps and the Pre-Alps are Bormio in the upper Valtellina, Livigno in the homonymous valley, the Aprica between Valtellina and Valcamonica, Ponte di Legno at the Tonale pass, Selvino in Val Seriana etc. Highly attractive is also the Spa tourism, especially in the centers of San Pellegrino Terme, Trescore, Gaverina, etc.