Urola Kosta borders the Cantabrian Sea to the north, with Urola Medio to the south, Donostia-San Sebastián to the east and Debabarrena to the west. The top and cross of Pagoeta, at the heart of Pagoeta Nature Park.
It occupies two sections from a morpho-structural standpoint. To the north, a series of coastal mountains from the Tertiary period, that is to say, the western cape of Igeldo-Mendizorrotz; broken by the mouth of the Oria river. From that point on, the mountainous terrain hardly continues, above Orio, appearing again on the so-called Getaria sector, on mount San Antón (the Mouse of Getaria). This sector is broken by the mouth of the Urola river, and from that point on it continues along cape Marianton and San Telmo beach. To the south of the coastal range, on the external passages (Oria sector) and Zarautz plains form a depression. From a lithologic standpoint, the external passage is made up of marlstone and a mixture of limestone. Which is precisely where the sea sector enters into play; and that’s how it spreads, with the help of a concentration of sand, at Zarautz beach. The side on which the Zarautz diapir is also located.
The Urola river is formed on the northern slope of the Aizkorri range (in the Urola Garaia area), due to the flow of karstic water. Although it collects waters from the Altzolaraz, Ibaieder (with a dam), Errizil and Urrestilla rivers, it does not have a very high average flow: 8.5 cubic meters pers second. It flows into Urola Kosta, firstly crossing Aizarnazabal and then Zumaia, leaving large piles of sand.
The Oria river crosses the northwestern section of the region. Forming a floodplain entering the sea; although marshlands still remain in this section. Orio beach is located here, protected by a large mound. In this region, to the north and in the lowlands there is a predominance of grasslands. The remaining land is made up of pine groves, pastureland or oak groves. Pagoeta Nature Park is declared area of special natural interest.
Aia: 2046 inhabitants.
Getaria: 2818 inhabitants.
Orio: 6000 inhabitants.
Zarautz: 23273 inhabitants.
Zumaia: 10066 inhabitants.