Located in the center of Madrid in front of the Royal Palace, the Vistillas garden overlooks the hills of Madrid. A very Catholic country, Spain is the focal point of many pilgrimages. Our study focuses on a monastery building dedicated to a community of monks and which would help to expand the capacity of pilgrims in the city by offering 50 places available. While monastic time is highly regulated and fragmented in many tasks, its animation and organization are similar to a complex ecosystem, such as a city in the city. The monks live there almost self-sufficiently with various activities and needs: beyond the liturgical practice, the monks need space for housing, cooking, toilets but also workshops and spaces of culture. Located in the middle of the garden, the volumetry of the monastery refers to an ancestral rock nearest to nature and far from urban activity. The treatment of interior spaces is made of light stone, typical of medieval buildings around the Mediterranean sea. Two large wells of light pass through space: these openings to the outside are oriented in such a way that only the divine elements, the sky and the nature, are emphasized.