The Alkyonides Gulf (Greek: Κόλπος Αλκυονίδων - Kolpos Alkyonidon) is a bay that connects with the Gulf of Corinth to the west. The bay is approximately 20 to 25 km long and 20 km wide. It stretches from Aigosthena to from east to west and from Cape Trachilos to the peninsula of Perachora from north to south. Three regional units surround the gulf: Corinthia to the south, West Attica to the east and Boeotia to the north. Except for the to the southeast, mountains surround the gulf. These mountains include the Geraneia to the south, Pateras to the east, Cithaeron to the northeast and Mount Helicon to the north. Beaches include Mikra Strava, Strava, Mavrolimni, Kato Alepochori, Aigosthena, Alyki and Paralia Korinis. The Alkyonides Islands, which are also known as Kala Nisia (literal transl