It is the sea between the island of Evia and continental Greece. It is divided into the North and South Gulf . Both bays end up in the Strait of Euripus where their waters join.

The main features of the Evoikos Gulf are calm, warm waters and unparalleled natural beauty. The colors of the water range from light cyan to deep blue. Its seabed is one of the most diverse in Greece and the coastline includes large, sandy beaches and smaller pebbled coves. In the north, trees often reach to the seashore while in the south steep rocks and heather are the main distinctive features.

In this diverse natural environment, a rich ecosystem has developed. Dolphins frequent the Evoikos Gulf and dozens of bird species are on its shores all year round.