Evia is the second largest island in Greece and the sixth largest in the Mediterranean. The area of ​​the island is 3,654 sq.km. and extends along the northeastern mainland of Central Greece, from the Gulf of Malia to the opposite coast of Rafina, separated from it by the Evian Sea.

Its shape is oblong with its two edges flattened and around its middle. It extends in a direction from northwest to southeast, having a total length of 180 km and a width ranging from 8 to 50 km. NW. It is separated from Fthiotida and Magnesia through the Oreos canal, while south through the Evian Gulf it is separated from Boeotia and Attica. It is separated southeast of Andros by the Strait of Kafireas. Its northern and northeastern coasts are bathed by the Aegean Sea.

Along with Lefkada are the two islands of Greece to which access is by road.

At the closest point to Central Greece is built the capital and largest city of the island, Chalkida, where there is one of the two links of the island with mainland Greece, the old bridge of Chalkida. Recently, the high bridge of Chalkida was built, with a total length of about 700 meters.