Between the 14th and the 17th century, Aretxabaleta was one of the ancient parishes in the Valley of Leniz, along with 16 others. This large number of parishes made their management difficult, and it was for this reason that in 1630 they were grouped into two districts: Aretxabaleta and Eskoriatza.

Today, Aretxabaleta has 7 ancient parishes located in idyllic countryside, and you are invited to visit their tower houses and churches. In Korueta, for example, the highlight is the church of Santiago with its 16th century altarpiece, which is reminiscent of the passage of pilgrims across the valley. Aozaratza, with its tower house and the chapel of the church of San Juan, is clear evidence of the prominence of the Otalora family lineage in the area. In Areantza, the church of Andra Mari with its splendid 15th century carvings can be admired, and in Larrino, the views over the Urkulu reservoir are truly spectacular.

The ancient parish nearest to the town centre is Isurieta, with its church of San Pedro. Slightly further on is Galartza, built on high ground over an outstanding complex formed by the 14th century church of Santa Lucia and the tower house.

Arkarazo can be reached from the hamlet of Portasol. The tower of the Church of San Millan was designed by the prolific artist Martin Carrera in the 18th century.