Donostialdea is one of the eight regions of Gipuzkoa, Basque Autonomous Community, corresponding to the basin of the lower Urumea along with a strip of basin corresponding to the Oria River, the region borrowing its name after the capital city of Gipuzkoa Donostia-San Sebastian, in Spain. The region comprises eleven municipalities extending in an area of 305.72 km² (see below, data released in 2006).