When a phone rang at the Department of Archaeology, University of Copenhagen in the summer of 1998 it was in fact heralding a novel development in West African and European archaeology. A voice informed that Danish road constructors had stumbled across some mysterious holes in Bénin and - at the instigation of the Patrimony of Bénin - requested specialists to investigate. From a West African regional perspective, Bénin, along with Togo, remains in a dire state in terms of archaeological research and so this first, and subsequent studies, have uncovered a wealth of dense description and images. These volumes are really a "first", and primary information cannot be ignored. Since the discipline of archaeology is still in its emerging state in Bénin, indeed in all West Africa, with no conventions on terminology or chronology, it was decided to focus on data, then on implications. Exploring caves, palaces, geology, burials, iron and ceramics, these volumes provide a much-needed archaeology study of Southern Bénin. The objectives of research were formulated in a simple manner: for whom, why, and when were the caves created?.