The remarkable, little known Cantabrian Mountains extend along the Atlantic coast of northern Spain for nearly 500 kilometres from the east Pyrenees to Galicia. In some parts they tower 2,500 metres above sea level. The mountains form a barrier between the cool, moist part of Spain, known as Espana Verde or “green Spain”, and the arid central plateau. Proximity to the Atlantic makes for high humidity. Generous summer rainfall on the northern side of the mountain range provides perfect conditions for abundant vegetation. Oak, chestnut, and beech forests grow in the lower altitudes while lush mountain meadows carpet the higher elevations. Only the highest summits are dry and barren, except in winter, when thick snow blankets the mountains.