A new excavation and survey has begun at the Sanctuary of Zeus on Mt. Lykaion in Arcadia, Greece. The fifth field season, summer 2008, will have three major aspects, excavation, architectural documentation and topographical survey in addition to ongoing geological, geophysical and historical surveys. The dates of the summer 2008 season are June 24 - August 7, 2008. In the ancient Greek region of Arcadia in the southern Peloponnesos, the sanctuary of Zeus on Mt. Lykaion stands out for its great fame, mysterious rituals and wide-ranging significance. This site, located to the west of Megalopolis in southwestern Arcadia on the modern-day mountain of Agios Elias, held fascination for the ancient Greeks and has continued to be important for modern-day scholars of archaeology, classics, and Greek religion. Pausanias described the sanctuary of Zeus in great detail in his Guide to Greece (8.38.2-8.38.10) and indicated that the whole mountain was considered a sacred place by ancient Greeks. It was identified in Greek mythology as the birthplace of Zeus (at Cretea) and, according to Pausanias, on Mt. Lykaion there was a stadium and hippodrome in which athletic games for the Lykaion festival were held, a sanctuary of Pan, and, at the summit, a formidable temenos and altar of Lykaion Zeus. In front of the altar, Pausanias says, there were two columns crowned by gilded eagles. Mt. Lykaion was investigated about 100 years ago by the Greek Archaeological Service under K. Kontopoulos, briefly in 1897 (AE 1898), and by K. Kourouniotes, in 1902 (Praktika 1903, 50 ff; AE 1904, 153ff). Kontopoulos dug a few trial trenches in the area of the hippodrome and in the altar. Kourouniotes then excavated a portion of the altar and the temenos a few years later. He found that the altar consisted of a mound of blackened earth, 30 meters in diameter at the top and approximately 1.5 meters high. The earth of the altar contained burnt stones, many small animal bones, tiny fragments of 5th and 4th century BC pottery, iron knives, clay figures, coins from Aegina, a clay figure of a bird, and two small bronze tripods. Kourouniotes found no evidence of human bones, only animal bones (mostly cow and pig). In the eastern part of the temenos, he excavated some trenches and found a number of bronze human figurines, some iron objects and roof tiles. He also excavated the two bases towards the east of the altar (probably those mentioned by Pausanias and first found by Kontopoulos). In 1909, Kourouniotes excavated the area to the east and below the summit of Lykaion, where the hippodrome, stadium, xenon, stoa, monuments and bathhouse were located (PAE 1909, 185-200). The sanctuary and grove of Pan, mentioned by Pausanias, were found by Kourouniotes southwest of the hippodrome. Based on the finds recovered by Kontopoulos and Kourouniotes, activity at the altar can be dated as early as the late seventh century BC. The site appears to have reached its peak of activity in the Classical period. By the time Pausanias visited Mt. Lykaion in the second century AC, the athletic contests had been transferred elsewhere and apparently the site was no longer in use. The sanctuary of Zeus on Mt. Lykaion was not systematically investigated again until 1996, when Dr. David Gilman Romano of the University of Pennsylvania Museum conducted an important architectural and topographical survey at the site. (Publication forthcoming in The Proceedings of the 2002 Arcadian Symposium held at the Norwegian Institute at Athens in May 2002). Romano had previously studied the stadium at Mt. Lykaion for his dissertation on Greek stadia and argued that it was a unique example and one of the most important in the Greek world (Stadia of the Peloponnesos, Ph.D. Dissertation, University of Pennsylvania, 1981). Dr. Romano and others have noted that the hippodrome at Mt. Lykaion is the only extant and visible example in the Greek world. Scholars of Arcadian cults and religion have also analyzed the site, resulting in numerous publications (e.g., M. Jost, Sanctuaires et cults d'Arcadie, 1985). Recent research on sanctuaries in Arcadia indicates that this site developed very differently from any other sanctuary in the region (M. Voyatzis, "The Role of Temple Building in Consolidating Arkadian communities," in Defining Ancient Arkadia, T.H. Nieslen and J. Roy (eds.) 1999). Anthropologists have studied the possibility of human sacrifice at Mt. Lykaion and the evidence of comparable accounts from other cultures. The fact remains, however, that except for Romano's recent survey, Mt. Lykaion has not been systematically investigated for nearly 100 years, and it has never been scientifically excavated. Given the importance of Mt. Lykaion, including its significance for ancient Arcadians of the Classical period who viewed it as a symbol of Pan-Arcadian unity, its standing among the Pan-Hellenic athletic festivals, the presence of several unique architectural elements, and its mysterious and secret rituals, it is time for a new investigation of this site by an international, multi-disciplinary team.