In Itsaso, worth seeing are the Church of San Bartolomé and its bell tower clock from 1730, one of the oldest in Gipuzkoa.
The temple dates back to the 16th century, but conserves prior remains such as the late Romanesque doorway.
It has three naves with semicircular arches and a polygonal apse. The altarpiece is from the last third of the 16th century. As a curiosity it should be noted, that there is a star engraved on one of the walls, whose origin is unknown.
This parish church houses an 16th century altarpiece. This altarpiece consists of a seat, three bodies, three columns and dust collector.
In this altarpiece, the centre stage of the seat is taken by the tabernacle, which does not belong to the altarpiece due to the era in which it was made. To the sides one may observe the Flagellation and the Ecce Homo.
In the first body, San Bartolomé occupies the central the image. He has a knife in his hand, which looks more like a machete and it is not easy to identify the saint by this symbol, who wants to be of his martyrdom. On both sides, two relief's reveal the Annunciation and Visitation of Our Lady.
In the second body, it reveals the Nativity and the Adoration of the Kings.
The decoration of the altarpiece is very good. Heads of the Angles in the friezes, shells in the niches... and very fine but very abundant polychrome, not only in the relief's but also in the friezes and lintels, where all the spaces are decorated with flower garlands. Perhaps this latter being a product of some restoration done later.
This altarpiece dating back to 1575 (stuffed and gilded) was made by the urretxuarra Juan de Lizarazu.