Mountains represent a significant share of the EU territory, population and economy. Most definitions, including the one established for the purpose of compensating natural handicaps for mountain agriculture (Less Favoured Areas (LFA), laid down by article 18.1 of Regulation (EC) No 1257/1999), rely on criteria relating to minimum altitude (between 500m and 1000m for mountain LFAs), minimum average slope (between 15 and 25 percent) or a combination of both minimum altitude and slope. According to the LFA definition, mountain areas represent 18.5 % of the total EU area. In the mountains, agriculture faces several limitations, related to the existence of permanent natural handicaps, which are not easily tackled with investments. Low temperatures and the limited length of the crop growing period combines with steep slopes with less fertile soils and the need for more complex machinery and more working time. This results in lower labour productivity and lower land productivity. Such limitations also imply that farmers have less choice on the productive sectors they can invest in. Finally, farms are smaller on average compared to on plains or flatter, lower-lying areas. Poor accessibility increases the difficulties of mountain farms and also affects the mountain food industries (increased collection and transport costs, smaller structures implying less economies of scale).