Doña Otxanda Tower is a beautiful building crowned with battlements. This is one of the numerous defensive structures of the walled nucleus of Vitoria-Gasteiz.
The married couple Andrés Martínez of Iruña and Catalina of Alava built the current tower in the 9th century on a previous tower, giving it the name of their daughter, Otxanda. The building was rebuilt in 1970.
It is currently home to one of the numerous museums in the Álava capital: The Natural Science Museum.
The natural science museum conserves valuable botanical, zoological and geological collections. With regards to its geological collection, most notable are the pieces from the amber archaeological site of Peñacerrada-Urizaharra. Its setting is also singular, since the museum is housed in the tower of Doña Otxanda.