The Mycenaean Cemetery of Voudeni, northeast of Patras near the village of the same name, is one of the most significant Bronze Age sites in the western Peloponnese and almost entirely overlooked by visitors. Excavated from the 1980s onwards, the cemetery consists of dozens of chamber tombs cut into the hillside and dating to the Late Bronze Age (roughly 1400–1200 BC) — the same era as Mycenae, Tiryns, and the Troy of Homer's Iliad. The finds from the site, including jewellery, weapons, pottery, and bronze vessels, are now in the Archaeological Museum of Patras and represent an extraordinary window into Mycenaean life on the Gulf of Patras.
The site itself is not signposted or developed for tourism, which is part of its appeal: you're visiting an archaeological site rather than a heritage experience. The hillside tombs are accessible with some scrambling, and the landscape around Voudeni — olive groves on the slopes above the gulf — is pleasant for a drive or walk. Go to the Archaeological Museum first to see what was found here; the context makes the site itself considerably more meaningful. Getting there requires a car; it's about 15 km northeast of Patras along the northern Peloponnese coast road.