Koroni Island

Koroni Island is a beginner-friendly dive site around a small islet near Marathon on the northern Attica coast. The islet creates a sheltered diving area with interesting underwater topography: gentle slopes, scattered boulders, and small overhangs descend from the rocky shores. Divers can explore different aspects of the island, with the lee side offering calm conditions and the more exposed side featuring slightly more current and larger marine life. Wrasse, damselfish, octopus, and moray eels are common residents. The islet's archaeological significance — ancient fortifications are visible above water — adds cultural interest to the diving experience.