The Cave of Baltzola lies forty minutes west of Onate and is reached after a beautiful fifteen minute walk through the greenest of countryside, company is provided by cattle and horses who graze freely and are inquisitive of passers by. They can be heard before they are seen due to the large cowbells tied around their necks. We, being city folk were scared to death of these gentle creatures, so much so one day that we made an enormous detour to avoid a mother and calf after convincing ourselves of the vicious nature of a mummy cow and her baby.

The first time you enter Baltzola three things hit you; firstly the size, secondly, the dark and finally the cool. The routes are either very steep walls or roof climbing and the climber uses tufas, pockets and flakes to reach the chains. Many of the climbs have been extended to provide increasingly difficult variations on the same theme. The handholds are nearly all smooth and friendly on the skin which I guess is due to the weathering effect of the water that formed the cave. This along with the cool temperature allowed for a greater number of attempts to be made on the same route. In fact the conditions in the cave were the best I have ever experienced during the summer months in Europe.

Baltzola is home to one of the most outrageous sport routes that you will ever see. Tas-Tas is the work of Ricardo Otegi, and after a wildly overhanging start climbs the roof of the cave towards the entrance. It covers over 30 metres of horizontal climbing and weighs in at 8c+/9a. When you have ticked that off many other classics await, Ijoronas, Ique Monas traverses rightwards where a very difficult move to a shelf proves the crux, it packs a lot in its 10 metre length to gain its grade of 7b. The 6b+ of La Vuelta Al Mundo En Globo is a gem with an unusual chimney and bridging section that reminded me of the techniques required on the Pembrokeshire sea cliffs. Sanson Jun Zan, 7c+ has one of the most awkward moves your likely to come across and requires of the climber a Harry Houdini ability to dislocate arms and hips to squirm into a peculiar hole in the roof and so gain the finishing jug. In the darker recesses of the cave lurks a climb that has no name and which necessitates an unusual training requirement, carrots. The climbing is hard, 7c+ but seeing the hand and footholds is harder, we would sit in a darker part of the cave before redpoint attempts in the hope that our engorged pupils would last through to the crux. They never did and the last half would see us flailing around to screams of "right, no further right you fool".