Ibarraundi Mansion is the result of various architectural transformations. It was built between the end of the 15th and beginning of the 16th century, and its interior encompasses many interesting reminders of the passing of time.

The Lord of Galartza and Juana de Ayala built their residence on this plot in Ibarraundia. The oldest section is the west wing, which displays the old entrance to the original tower house, with a pointed arch preceded by a flight of stairs. Another arch of the same period can be seen in what is now the audio-visual room.

Other elements added later are evidence of the many functions the building has had over the years. The openings on the ground floor give it a palatial feel and today it is the site of the Ibarraundi Museum.