Borrokosko 13; Bk 13

From the village of Ayechu, take the track that climbs to the Areta pass, leaving a turnoff to Larraun on the right and shortly after another to the village of Izal (chain). The track climbs and after several km reaches the Rasolanda col. Here a short descent begins to get past the W crest of Borrokosko at 1330 metres of altitude. Again a brief descent and the vehicle is parked between Arnazu and Borrokosko at 1283 metres, in some meadows on the left. Heading East from the parking spot, in barely 100 metres is the BK 13 sinkhole. Apart from this one and on the same heading, the not very visible alignment of dolines and pits follows, first along a clear path that is then lost to cross a fence (muga Salazar Urraul alto).