Valley and beech woods
The Sierra de Arangio peaks run through this municipality from north to south, dividing it into two distinct areas. The eastern side consists of valleys (over 800 m) where the terrain has been humanised to a large degree, with pasturage, farming hamlets and conifer plantations. On the western side (500 m) large expanses of the original beech woods remain. This is the site of the village of Olaeta and of most of the natural park land, including the highest peak in the area: Orixol (1129 m).
As in Gorbeia, the park area has a mountainous climate influenced by its proximity to the ocean, with rainfall of 1400 - 1500 mm per annum, heavy snowfalls and only slight changes in temperature.