The vineyards planted on the slopes of the Montagne de Reims are located south of the city of Reims. They are spread from east to west over almost 18 miles (30 km) long and 4 to 6 miles (6 to 10 km) kilometres wide. The mountain is bordered by the Marne and the Vesle rivers. The deep limestone soil retains a maximum of water which benefits the vines. The continental climate, temperate and cool, is ideal for the Pinot Noir which produces the greatest Champagne wines here. Frosts are rare and temperatures are maintained at over 33°F (1°C) in winter.