The vineyards of Medio Penedes are sited slightly higher (820-1,640 feet/250-500 metres) and are responsible for the bulk of the quality Spanish wines. Higher still are the vineyards of Alt Penedes (1,640-2,624 feet/500-800 metres) that are much cooler. Here, on the edge of the Meseta, the best grapes are produced for the best quality Spanish wines. Although generally speaking the lowest vineyards are the hottest and the highest the coolest, there are so many microclimates in this area of 5,000 hectares, that the most discerning wine-makers can enjoy the challenge of finding the best combination of grape variety, soil, and microclimate. The soil varies far less than the climate. The coastal strip has a more sandy top layer while the higher ground comprises more clay. The underlying rock beneath throughout is chalk and is rich in trace elements, which are beneficial for growth and the health of the vines.