Two sanctuaries anchored the cult of Zeus. At Olympia in the western Peloponnese stood the great altar and, from the fifth century BCE, the gold-and-ivory seated Zeus by Pheidias, counted among the seven wonders of the ancient world; the Olympic Games were held there as a festival in his honour, under a sacred truce that suspended war among the competing cities. At Dodona in Epirus was his oldest oracle, where, Homer already knew of it, his will was read from the rustling of a sacred oak and the sounds of bronze vessels, interpreted by priests the Iliad calls the Selloi.
The everyday reality of worship was sacrifice. The characteristic offering to the Olympian gods was the burnt thigh-bones and fat of an ox, the meat then shared among the community, a division of the animal that Hesiod explains through a myth of Prometheus tricking Zeus.
Modern reception has tended to flatten Zeus into a philandering cartoon, and the myths do dwell on his many unions. It is worth holding alongside that the same figure was the Greeks' guarantor of oaths, of hospitality and of justice itself, Zeus was invoked precisely when a Greek wanted to say that something was right, not merely powerful.