Threatened with destruction through exposure to 175,000 visitors a year, the extensive polychrome cave paintings in Santillana del Mar in northern Spain were closed to the public in 1978. Less than 300 metres away, a reconstruction of the cave has now been opened, together with a palaeolithic museum and a research institute, all housed in a series of flat, strip-like buildings stepped down the hillside. The research institute and administration areas, suspended beneath the large, sloping planted roof over the new cave, are illuminated by linear skylights. On the other side of the central entrance tract are the exhibition areas, a cafeteria and a multi-purpose space, accommodated in three finger-like structures which are also stepped down the hill. The north-lights projecting from the flat grassed roofs of these structures allow daylight to enter the linear museum spaces, where it is diffused by raking slabs.