It is 31 km long with an area of 56 km2, and forms part of the Szentendre District of Pest County.

[1][2] The Megyeri Bridge, carrying Budapests's M0 motorway ring road, crosses the southern tip of the island, but there is no access to the island's road network from it.

The island is connected to the mainland by the Tildy Bridge [hu] that crosses the Szentendre branch.

[1][2] Several villages are located on the island including (from north to south) Kisoroszi, Tahitótfalu, Pócsmegyer, Surány, Szigetmonostor and Horány.

In addition to farmland, orchards and vineyards, the island's most important role is to supply Budapest and the neighbouring towns with water.