From a cycling point of view, Monte Oiz is a hard but enjoyable climb to ride. Stage 17 of La Vuelta in 2018 finished on top and is one of the most prominent summits of the region at 950m above sea level.
You got three sides to Monte Oiz. The climb from Lurreta is the easiest of the three sides; however, it is still a tough climb. There are steep gradients via Munitibar and Gernika, but here there are also gentle sections between them, enabling a kind of recovery which is impossible in the last 5km from the other two sides. You will start with some steep pitches, before passing through some pleasant villages. After Santa Kataline the climb takes on a different face, rising steadily through forest before bursting above the trees to the wind turbines.
From Gernika the climb is much harder. The first 15 kilometers are quite gentle with no real difficulty. However, you then turn off onto a narrow road with very steep sections and a bumpy road surface which requires even more power to overcome. The average gradients per kilometer are 14%, 13%, 10.9% and 12.5%. At some point the gradients pitch over a 20%.
From Munitbar the climbs runs for about 9 kilometers. The steepest parts are in the second half of the climb, so do safe some energy. You will now repeatedly pitch over a 15% gradient.
It’s great to cycle in the Basque Country’s cycling heartland. Other legendary ascents are close by such as Arrate and Puerto de Urkiola. Enough potential options to incorporate in a circular ride around here.