St. Eunan's Cathedral, also known as Raphoe Cathedral, is one of two cathedral churches in the United Dioceses of Derry and Raphoe in the Church of Ireland. Located in Raphoe, County Donegal, it is dedicated to Saint Eunan, who was the abbot of Iona in the 7th century. The cathedral has a complex history, with the oldest part dating back to the 12th century, and subsequent rebuilding and alterations from the 17th to late 19th centuries. The virtual re-building in the 17th century, directed by Bishop George Montgomery, played a significant role in its development. After restoration efforts in the 1890s, funded by the Knox family, the cathedral features a long narrow form, stained glass, and a decorative western doorway.
Medieval features, including a bishop's seat, shamrock-topped columns, and a piscina, are still present. Nearby remnants include a consistorial court building and a bishop's palace.
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.