highest mountains in Portugal. The range lies in the north-central part of the country, between the basins of the Tagus and Mondego rivers. The western continuation of the Central Sierras (Sistema Central) of Spain, the range runs about 40 miles (65 km) from northeast to southwest and is between 10 and 15 miles (16 and 24 km) wide. On the highest peak, Torre (Alto da Torre), which rises to 6,539 feet (1,993 m), a tower has been constructed. With an annual rainfall of more than 90 inches (2,300 mm) above 4,000 feet (about 1,200 m), the range is one of Portugal's chief pastoral districts, the seasonal herding of sheep and goats still being practiced there. The Serra cheese is the mountains' most famous product. The large Serra sheepdogs are an admired breed. Designated a natural park, the range attracts walkers in the summer months and skiers and snowboarders to the snowy slopes below Torre in winter.