Lagonisi (Greek: Λαγονήσι meaning "rabbit island") is a seaside residential area in the southern part of Kalyvia Thorikou in East Attica. It is situated close to the shore and on a peninsula by the Saronic Gulf. Lagonisi is located approximately 30 km southeast of Athens and 35 km northwest of Cape Sounio. Being filled with luxury homes, beaches as well as a 5-star hotel that lie within the Saronic, it is one of the most expensive areas in Attica Prefecture. Restaurant facilities, cafeterias and bars are located mainly on the heart of Lagonissi, close to Kalyvion Avenue (the road connecting Lagonissi with Kalyvia Thorikou).
Lagonisi has many beautiful sandy beaches including those of Pefko, Agios Nikolas and Galazia Akti which are organised. In recent years, the Greek government-debt crisis has led to the privatisation of many state owned properties, including beaches. The state is oriented towards their privatisation, although locals' opposition makes beaches' future property status uncertain.