The prefecture covered the south-western part of the agglomeration of Athens, several islands in the Saronic Gulf (Salamis, Aegina, Agkistri, Poros, Hydra, Dokos, Spetses, Spetsopoula), Methana and Troizina on the Peloponnese peninsula, and the islands of Kythira and Antikythera south of the Peloponnese.