Terra Sanctus - sacred earth - refers to the rich religious history steeped in the culture of the area and the dramatic hillside vineyards from which the old vines of Garnatxa and Carinyena are sourced for Clos la Rae. The average vine age is 50 years, with some up to 80 years on unterraced margins. Soil is the classic llicorella slates with very low water retention, forcing the roots deep - as much as 30 meters - in search of water and nutrients. Viticulture has an ancient history in the Priorat, and winemaking dates to the 12th century, when monks founded the Carthusian Monastery of Scala Dei in 1194. The prior of Scala Dei ruled as a feudal lord over seven villages in the area, which gave rise to the name Priorat. The basis for the soils (called llicorella in Catalán) are reddish and black slate with small particles of mica, which reflects the sunlight and conserves heat. Vines are forced deep into the ground in search of water and nutrients, in many cases well over 30 meters.