The altarpiece of the Chapel of the Pieta in the parish church of San Miguel is extraordinary. The chapel was commissioned by the Oñati-born Rodrigo Mercado de Zuazola, head of the Royal Treasury of Granada and subsequently Bishop of Avila. It is situated at one side of the high altar, in the same site as the Bishop’s mausoleum. The altarpiece is a wood carving created by Gaspar de Tordesillas, born in Valladolid, and represents the Passion of Jesus and the life of the Virgin Mary.

A short distance away, in the Chapel of the Sancti Spiritus of the University, there is another masterpiece from the mid-16th century: the Renaissance altarpiece of Saint Michael and the Holy Spirit, attributed to the French artist Pierre Picart. In this pure and ordered structure, the images placed in niches on the main panel are the main feature. The movement expressed in the folds and figures give the whole ensemble great dynamism, suggestive of the Mannerism style.

In the church of the Monastery of Bidaurreta there is another fascinating example of Renaissance art: the altarpiece created by Juan de Olazaran, which was first situated above the high altar from 1533 to 1753, and later moved to the transept. The genius of the artist comes to its own with the image of the apostles in the predella of the altar.  He places them in groups of three, and shows each one with his attribute: Saint Peter with the key, Saint James with the pilgrim’s staff and hat, and Saint John with the chalice.

Worth mention is the Altarpiece of San Miguel, found above the high altar of the parish church of San Miguel de Oñati. This altarpiece is in the Churrigueresque Baroque style and was created by Juan Bautista de Suso between 1714 and 1717. The structural design is polychromed with protruding Solomonic or helical columns which give the building a feeling of great movement.

The Altarpiece of the Coronation above the high altar of the church of the Monastery of Bidaurreta was also created in the 18th century. This is an imposing work because of the Baroque-Rococo style of its architectural design, as well as the outstanding quality of its sculptures, attributed to Jose Sierra.

The high altar of the Basilica of Arantzazu is decorated with one of the most remarkable altarpieces of the 20th century. Created by Lucio Muñoz during the 1960s, it is evocative of the surrounding landscape across 622 m2 of polychromed wood. The Virgin of Arantzazu is placed in a central niche.