The lighting project is located in Buitrago de Lozoya, a small town of the autonomous community of Madrid in central Spain. It is closed to north mountain range and it lies on a peninsula surrounded by the Lozoya river. The town is one of the few in the community that have maintained its walls, which are of Moorish origin (11th century) and have been restored in the 15th century. Between its iconic monuments, Buitrago de Lozoya has kept as well the Buitrago del Lozoya Castle, a Gothic-Mudejar structure dating from the 15th century and the church of Santa Maria del Castillo which was built in 1321 in the same style.Last, but not least the town includes also the Picasso Museum. This small museum contains works by Pablo Picasso from the collection of Eugenio Arias, a citizen of Buitrago de Lozoya who was barber by profession and friend of the artist.The aim of the project was to provide the strategic and historical spaces of Buitrago del Lozoya not only functional but also decorative lighting. Especially the wall, church Santa Maria del Castillo, and the Castle. The objective of this intervention is to achieve the highest quality of Buitrago de Lozoya´s tourism, enhancing its heritage lighting for its conservation and appreciation, especially during the night, providing a new character to these public spaces and enhancing its use during the night for public activities and shows, promoting a new cultural program for Buitrago de Lozoya.The project had to solve not only the lighting project for the events that may take place in the castle, but also to provide anew emergency lighting system for the evacuation of 1,700 people capacity. The project is solved with a perimeter ring made of corten steel, supported by the existing terraces outside the castle. Inside this ring are located all necessary cables of the lights mounted on the perimeter of the castle. Its circular geometry reduces the meters of cabling and allows a radial disposition for the installation of the lights.The geometry of the ring is adapted to the shape of the existing square in front of the castle and enhances its circular shape. Thisunique round shape is due to the permanent installation of an arena for local festivities and bull-fighter shows in the first half of the twentieth century.The ring is made of corten steel and is perforated. It allows the installation of a ring-LED system (Lighting Emitting Diode), not only for the ambient lighting but also as a part of the emergency lighting system as it is connected to UPS (Uninterruptible Power Supply). The decision of installing the LEDs system responds to the need and commitment with the environment. The LED installation involves significant energy savings, in some cases it can save around 80 or 90 % of energy, and It has longer- lasting, up to 100.000 hours, which implies a larger cost savings on refills. Besides, it is made in a 96% of its composition of recyclable material. This is why it is one of the lighting systems which are less harmful to the environment.The four corners of the castle are enhanced by four vertical lighting lines, made of the same material as the ring. These four points of light enhances the verticality of the corners and change the scale and perception of the castle, improving orientation and the perception of the space of the visitor.This lighting installation provides a new character to this unique space, and as the light of the day is always changing, the light installation is not permanent, it changes the intensity and color, creating a play of colors. This dynamic installation brings us to the current style of living, changing and adaptable and enhances the need for differentiation and for the application of the design as a part of our lives.These light lines enhance the architectural volumes of the castle and create a unique vision of the castle and the square which we try to retain. The vision of a building during the night could be permanent or may be ephemeral, and in this case, becomes permanent, as it remains in our memory.