There's a ferry to Paxi from Parga and boat tours up the Aherondas to the Nekromanteion of Ephyra/Sanctuary of Persephone and Hades with bird watching opportunities en route. The site --open at least from 9am to 2pm (more if staff permits), admission 2 euros-- is refreshingly unfrequented by hordes of tourists, and the boat trip very enjoyable. It is located above the village of Mesopotamo, 22km southeast of Parga on a hill. The mouth of the fabled River Styx (the river of Hades, the underworld), was above it. Myth has it that the ancient river of Akheron was here, from which Charon rowed the dead across to Hades. There was an oracle of the dead here from Mycenaean to Roman times, and Homer wrote of Odysseus visit to Hades (which can be easily evoked from the arrangement of the site and its purpose). The name itself , from 'nekro' (dead) and 'mandevo' (to guess), describes its ancient function.
The hill of the site is above the confuluence of the Kokrytos and the modern Akherondas rivers. There was once a lake here, which once encircled the oracle, its boundaries obvious when looking out at the site. The river flows to the sea through willows and poplars, though the site itself has cypresses, which are emblems of the dead throughout the Mediterranean. The Nekromanteion itself is an amazing labyrinthine creation, with windowless rooms off of its winding corridors, both above and below ground level. The arches still stand and the layout is still quite easy to see. Polygonal masonry was used beautifully in its construction, dating to Hellenistic times, the place was ruined by fire in 168BC. At its center is a very thick-walled structure comprised of an undivided central corridor with three rooms on either side, from which metal steps led down to a damp, vaulted underground chamber, but these steps were added later, the original being the bronze windlass found there. Evidence was found of offerings of grain, sacrificial animals, and some kind of liquid, perhaps honey. Two terracotta busts of Persephone were also found here.
Accounts from the time of the sanctuary related that pilgrims, who had come to consult with the dead, slept for a night in those windowless rooms, and who, after their votive offerings were taken from them, would go fumbling and groping along the twisting corridors into the center of the sanctuary, and then, disoriented by vapours from some order of hallucinogen, would be lowered with the use of the windlass into the antechamber of 'Hades' (Adhis in Greek) to experience whatever magic had been concocted up by the priests. A medieval chapel sits at some distance up at the top of the sanctuary, with some 18th century fresco fragment, below with some huge pitharia (clay storage urns) sit in their ancient spots.