Olympia, the mythical sanctuary of Zeus and the birthplace of the Olympic Games, lies in a verdant valley on the western Peloponnese at the confluence of the rivers Alpheios and Kladeos. A landscape of great natural beauty, the whole valley was densely wooded in ancient times. The leaves of the wild olive trees were used to make the wreaths that crowned Olympian champions; hence the site was named Altis, meaning grove. It was also named Olympia after Mt Olympus, the abode of Zeus. Dedicated to Zeus, the king of the gods, it sprawls over the southwest foot of Mount Kronos, at the confluence of the Alpheios and the Kladeos rivers, in a lush, green landscape. Although secluded near the west coast of the Peloponnese, Olympia became the most important religious and athletic centre in Greece. Its fame rests upon the Olympic Games, the greatest national festival and highly prestigious worldwide event which is held every four years to honour Zeus. The origin of the cult and of the festival goes back many centuries. Local myths concerning the famous Pelops, the first rulers of the region, and the river Alpheios, betray the close ties between the sanctuary to both the East and West. The archaeological site of Olympia, one of the largest in Greece, yielded a singularly rich concentration of monuments and works of art, such as the famous statues of Hermes by Praxiteles and Nike by Paeonius. Olympia is an outstanding example of a great Pan-Hellenic sanctuary of antiquity, with its multiple functions: religious, political and social.