Where does the last name arizmendi come from?

"Arizmendi" and some related forms (such as "Arismendi", "Aritzmendi" or "Haritzmendi") is a common surname in the Basque Country (Spain and France) and Navarra (Spain).

It is formed by the Words "(h)aritz", which means "oak", and "mendi", that can be translated as "mountain" - so, the whole surname could be interpreted as "mountain with oaks".