Just offshore from the old castle, a small inhabited island in Lake Pamvotis is one of the most picturesque corners of mainland Greece. A handful of monasteries scattered across the island's wooded slopes — Saint Nicholas of Filanthropinon (with extraordinary 16th-century frescoes), Saint Nicholas Stratigopoulos, Eleousa, Pantelimon — span the Byzantine and post-Byzantine eras.
The village on the island has narrow lanes, lakeside restaurants serving freshwater fish (trout, eels, frog legs), and a few shops selling traditional silver and embroidery. Boats run from the Mavili lakefront promenade every half hour in summer, less often in winter. The crossing takes 5–10 minutes; a quick visit feels like time travel to a quieter Greece.