In the vicinity of Oñati square is one of the most beautiful town halls in the region. Created by Martin de Carrera in 1764, it follows the same structure of all council buildings of that period: three stories finished off with a pediment adorned with the coat of arms of the district. The façade stands out especially for its delicate and very beautiful details in Rococo style.

At the centre of the town is the Plaza de Santa Marina surrounded by three exceptional mansions from the 18th century: Madinabeitia, Antia and Baruena

There is no doubt that the best example of 20th century contemporary Basque art is  the Sanctuary of Arantzazu. This modern basilica, 9 kilometres from Oñati, is the result of a project by the architects Sainz de Oiza and Luis Laorga between 1950 and 1955.