Nestor Basterretxea Arzadun (Bermeo, 1924 - Hondarribia, 2014) was a Basque artist. In the 1950s and '60s, he spearheaded along with other artists such as Jorge Oteiza, Remigio Mendiburu, or Eduardo Chillida, an avant-garde artistic movement concerned with the crisis of Basque identity, and formally a special focus on large volumes and the concept of emptiness.