This is the final piece from the Basoa series, the title of which means forest in Basque. This large-scale steel forest was conceived by the artist to sit in dialogue with nature, surrounded by trees. The large dimensions facilitate an interaction with the natural elements, and its organic forms are a clear example of the influence of nature in Chillida's work. The sculpture also alludes to the metaphor of the tree that Chillida so identified with and used to describe himself. In effect, the artist saw himself as being like a tree, rooted in the earth of his native Basque Country, but with branches extended towards the world. The title of the series is a Basque word and another demonstration of how his origins influenced his method of expression. While the artist himself did not speak the Basque language, he wanted his art to. Another aspect worthy of attention in this piece is the presence of three interacting elements. The symbology of the number three—a number with strong connotations and which is connected not only with mathematics but with philosophy and religion—becomes clear here. For Chillida, this magical number, inherently more open to dialogue and more tolerant, broke away from the duality of the number two.