Nestorio is a small picturesque village 28 km southwestwards of Kastoria, at the banks of the river Aliakmon, in the Kastoria regional unit of Macedonia, Greece.
The village is particularly famous for its annual late-July rock festival, River Party. River Party started in 1978. Most people camp out on specially prepared grounds in the forest near the stage. The bands come from the Greek rock scene, especially from Athens and Thessaloniki and with foreign guests, including from the wider region. Visitors also participate in extreme games including archery and rafting.