Surrounded by the mountain ranges of Urbasa
, this little hamlet lies at the foot of Mount Alzania at the confluence of the Sakana
and Alzania rivers and is the most important settlement in Burunda. It is a crossroads of both road and rail connections between Navarre, Gipuzkoa and Araba/Álava which has made it an important industrial hub.
The centennial hamlet of huge houses with vast doorways and little bay windows huddles round the austere parish church of La Asunción
Inside, the church houses a superb Romanist altarpiece whose polychromatic sculpture is of inestimable value.
In the Plaza de los Fueros is an unusual sculpture by José Ulibarrena. Using an ancient walnut tree that used to stand here, it features various figures embodying the essence of Alsasua: deep-rooted customs, mythology, nature, pelota and music.
In the heart of the town a "Japanese" electric locomotive has been installed in a garden. It was one of the first of its type to travel the Spanish railway network.
In the vicinity of the town is the chapel of the miraculous Christ of Otadia
, whose namesake is featured in a 15th century Baroque altarpiece.