Alkiza is a rural municipality in the centre of Gipuzkoa, northwest of the Tolosaldea County, in the Basque Country. It is 27 kilometres south of San Sebastian. In 2019 it had 373 inhabitants, of which 88.8% were Basque speakers. Alkiza is an independent municipality since 1731; previously it depended on Tolosa and San Sebastian. Alkiza is connected with Anoeta and Asteasu through the GI-3630 road. The Asteasu branch was inaugurated in 1952 and the Anoeta branch in 1957. Until then, farm roads and paths linked Alkiza with the nearby villages. The village is 340 meters above sea level and there are the school, the town hall, the pelota-court and the parish church. The municipality has more than 40 scattered farms and houses. Its inhabitants are nicknamed in Basque oiloak (chickens). The village's main festival is on September 8. Geography Alkiza is located in the east of Hernio-Gazume massif. The municipal area is mostly steep, with the flattest area in Arana neighborhood. The local climate is typically Oceanic. As Hernio is a limestone formation, there are in Alkiza numerous karst structures such as caves, chasms and sinkholes. The Leize Haundia 2 / Sabe-saia complex is the most important karst structure in Alkiza. The two caves form a system 340 m deep, 2 km of galleries and a stream inside. The most outstanding summits in the municipality are Herniozabal (1,010 m), Herniotxiki (820 m), Enaizpuru (731 m), Alluts (687 m) and Beleburu (619 m) to the west and Mendiola (431 m) to the east. A quarter of the surface of Hernio-Gazume Special Conservation Zone (Nature 2000) is located in the municipality of Alkiza. Hydrology As mentioned above, Alkiza is a karst area, so the rain and thaw waters go underground to a large extent. For this reason, some streams and creeks only carry water in the event of intense precipitation and, in others, there are surface waters only in some sections of the course. There are two main streams in Alkiza: Mandabe stream runs through Arana neighborhood and discharges its waters in Anoeta to Oria river. It is born in the source called Bidania erreka, where the waters of the Leize / Haundia 2 / Sabe-saia complex emerge. Among the inhabitants of Alkiza it was thought that the waters of this source came from the other side of Hernio, specifically from the village of Bidania, and hence its name. Aranguren stream is