The white walls of São Jorge Castle Archeological Site float above the visible foundations, touching the ground on a mere six points
Set on a prominent hill overlooking the Tagus estuary, Lisbon’s Castelo de São Jorge was originally a Moorish citadel. Yet the site also bears traces of earlier civilisations, marking the first recorded human occupation of the city. Successive waves of colonisation have left a complex historic and cultural legacy. Following the Reconquista, the citadel became a Christian fortress and royal palace. In the late 14th century it was dedicated to the nationally esteemed warrior São Jorge (Saint George), and formed a setting for great state occasions. The famous navigator and explorer Vasco da Gama was received there by King Manuel I on his return from discovering a maritime route to India.
But during the 16th century, when a new royal palace was built on the edge of the River Tagus, the hillside redoubt began to lose its significance. The Lisbon earthquake of 1755 severely damaged the castle, and its physical decline continued until the 1940s, when an extensive renovation programme finally transformed it into one of the city’s most popular tourist attractions. More recently, archaeological interest has focused on the Praça Nova area of the castle, where a rich strata of Iron Age settlements, Moorish houses and remnants of a 15th-century palace occupied by the Bishop of Lisbon have been gradually excavated, forming a visible testament to the site’s extraordinary evolution.
Lisbon-based João Carrilho da Graça’s practice, JLCG Arquitectos, was commissioned to devise structures that would make this fragile and disjointed palimpsest both physically presentable and museologically comprehensible to visitors. Working with landscape architect João Gomes da Silva, Carrilho da Graça has added a series of new elements, all very consciously of their time, but inculcated with a reductivist, neutral spirit that plays against the desiccated remains and subtly enhances the relationship between old and new.
The first move was to delineate the boundary of the site with a low wall of Cor-ten steel. The blade-like planes of Cor-ten thread precisely around and through the site, lining the sides of shallow excavation pits and forming a hovering structure to protect the remnants of a mosaic floor that once formed part of the Bishop of Lisbon’s palace. The underside of the cantilevered Cor-ten structure is covered in a black mirror, enabling visitors to inspect a reflected image of the mosaics at closer quarters.
Counterpointing the roughness and friability of the excavated remains, the same formal and material precision characterises other new elements, such as limestone steps, landings and seating. The most conspicuous new addition is a pristine, white walled box, itself resembling the temporary structures of archaeological digs, constructed over the foundations of a pair of Moorish houses. Inside, partition walls reproduce the internal layout of the dwellings and new walkways steer visitors around the remains. Overhead, gauzy, polycarbonate roof panels temper the light. The cool white labyrinth exhibits a simplicity and finesse typical of the best modern Portuguese work. Carrilho da Graça describes it as ‘Conjectural, abstract and scenographic. The white walls float above the visible foundations, touching the ground on a mere six points.’
Not only do the new parts safeguard the site, they also add an experiential dimension that brings its rich history more resonantly to life. Deferring to the past can be challenge, but the new architecture succeeds on its own terms, and the project recently won the 2010 Piranesi Prix de Rome, prevailing over 17 other contenders including Rafael Moneo and Gigon/Guyer Architekten. Awarded annually by Italian school the Accademia Adrianea, this international prize focuses on the relationship between architecture and archaeology. In particular, Carrilho da Graça’s scheme was recognised for the clarity, sensitivity and refinement of the new additions, and the way in which they connected with the existing archaeological remains and addressed the wider landscape of the castle.
Architect JLCG Arquitectos, Lisbon, Portugal
Structural engineers José Pedro Venâncio, Paulo Mendonça
Landscape architect João Gomes da Silva
Photographer Fernando Guerra