The semidetached island of Agios Ahillios is Prespes’ main attraction and its surrounds are excellent for birdwatching. The grand, concave outer wall of the ruined Basilica of Agios Ahillios stands on its eastern shore, with some half-toppled walls, columns and a stone floor. It's a legacy of the 10th-century Bulgarian tsar Samuel, who expanded his empire across much of the southern Balkans, chronically sparring with Byzantium.
From Agios Germanos, cross the connecting strip between the two lakes and turn immediately left onto a 1km-long wooden bridge. A signposted path to the left hugs the east coast and leads to the basilica and other church ruins. Alternatively, turn right off the bridge for the shop and taverna . Agios Ahillios is sparsely inhabited, though August's Prespes Festival features a headlining concert in the amphitheatre-like basilica.
