This fourth volume (Proceedings 4) presents the results of an international conference held at the Museo de los OrIgenes (Casa de San Isidro) in December 2008. The work is divided into three parts: Four studies on general aspects of the 'rock world' in the Iberian Peninsula, the chronology of the caves artificially created, the 'troglodyte' in the Greco-Roman tradition, and the chronology of rock-cut tombs. The second part looks at eleven studies of various regions and 'rock complexes' in the Iberian Peninsula ('San VItor', in San Lorenzo da Barxacova, Parada del Sil, Ourense; 'El Bierzo';...