37°39′07″N 24°01′34″E / 37.652°N 24.026°E
Cape Sounion (Modern Greek: Aκρωτήριο Σούνιο Akrotírio Soúnio [akroˈtirʝo ˈsuɲo]; Ancient Greek: Ἄκρον Σούνιον Άkron Soúnion, latinized Sunium; Venetian: Capo Colonne "Cape of Columns") is the promontory at the southernmost tip of the Attica peninsula, 8 kilometres (5.0 mi) south of the town of Lavrio (ancient Thoricus), and 69.5 km (43.1 miles) southeast of Athens in the Athens Riviera. It is part of Lavreotiki municipality, East Attica, Greece.
Patroklos (Greek: Πάτροκλος) or Gaidouronisi (Γαϊδουρονήσι, "donkey island") is a small, private island located in the Saronic Gulf, Greece. It is situated about 65 km from Athens and 3 km from Sounion and is part of the Attica region.
In ancient times, the island was known as Patroklou Charax (Πατρόκλου χάραξ, meaning "Camp of Patroclus") or Patroklou Nesos (Πατρόκλου νῆσος, meaning "Island of Patroclus"), after the Ptolemaic admiral Patroclus, who established a fortified base there during the Chremonidean War.