Solid church in granite built inside the medieval town walls. Work began in 1488 under the guidance of Biscay master Tomé de Tolosa, and using parts of a primitive Romanesque chapel (remains are visible in the north side); it pursued slowly, until the completion of the tower of the main façade in 1556. Important architects involved in the construction include João de Tolosa and Pero Galego. Inside, the building is a basilica with main nave and two aisles, and is notable for its inlaid ceiling (1565) showing oriental influences. The Mareantes Chapel, built by the corporation of seafarers, is one of the earliest renaissance works in Portugal. The church was classified as a National Monument on June 16, 1910.
References:The Church of St Donatus name refers to Donatus of Zadar, who began construction on this church in the 9th century and ended it on the northeastern part of the Roman forum. It is the largest Pre-Romanesque building in Croatia.
The beginning of the building of the church was placed to the second half of the 8th century, and it is supposed to have been completed in the 9th century. The Zadar bishop and diplomat Donat (8th and 9th centuries) is credited with the building of the church. He led the representations of the Dalmatian cities to Constantinople and Charles the Great, which is why this church bears slight resemblance to Charlemagne's court chapels, especially the one in Aachen, and also to the Basilica of San Vitale in Ravenna. It belongs to the Pre-Romanesque architectural period.
The circular church, formerly domed, is 27 m high and is characterised by simplicity and technical primitivism.