Adarra

Adarra (short for "Adarramendi", meaning 'mount of horns' in Basque) is a mountain south of the city of San Sebastian in the Basque Country much appreciated and popular with the donostiarras and other neighbouring inhabitants. It is flanked on the north by the minor mount Oindi or Onddi (Basque pronunciation: ['onɟi], 545 m) and Onddo (781 m) on the south, all of them located at the top of a long mountain range of modest height establishing the division between the Urumea and Leitzaran valleys, which extends south right to the vicinity of the Navarrese town of Leitza.

Geology and vegetation

That disposition of the big geological formations sticks to a distinctive north-south pattern of the short Gipuzkoan valleys ending up in the Bay of Biscay. The present area stands on the westernmost end of the Pyrenees, where outcrops of slate, sandstone, conglomerates, red silt and other materials can be found, largely from the Paleozoic Era and Mesozoic Era.

The vegetation landscape is split in two distinctive sides, the first one locating on the Eastern slopes and the second on the Western part. On the former patches of autochthonous forest and vegetation abound, while on the latter (especially on the way down to Leitzaran) pine tree used for logging (aka Pinus radiata) prevails. There are noticeable grassland strips for grazing sheep and horses interspersed with forest.