In September the Álava side of the Gorbeia nature park sees a unique natural phenomenon: the roaring of the deer. This is the mating season for about 600 deer living in the area.
In order to protect the species and stop them dispersing at this time of year, the Álava provincial authority takes different steps to minimise disturbance of the animals. At the same time it organises guided tours to watch the roaring from special observation points, in small-group visits for between fifteen and twenty people.
The visits take place at dusk and there is a draw for places.