The Monastery of Dumio (São Martinho de Dume), is a former paleo-Christian monastery in the civil parish of Dume, municipality of Braga, in northwestern Portugal. Originally a Roman villa, it was the base of a basilica by Suebi tribes, and later Christian monastery headed by Martin of Braga in the 6th century (c. 550–560). The re-discovery of the Roman ruins in the late 20th century resulted in archaeological excavations that unearthed its former use.
The ruins are located around the Lugar da Igreja or Lugar do Assento on the square occupied by the parochial church of Dume. Occupying a rural landscape, the space is an ample property that include the Church of São Martinho de Dume, constituted by a central nucleus of the courtyard, the chapel of Nossa Senhora do Rosário and backyard of the Casa do Assento, on the same block occupied by the local cemetery.
The archaeological ruins in Dume encompass a complex of structures that include: a grande Roman villa (with a habitational zone) and bathhouse; remnants of a granite basilica in the form of a Latin cross (oriented east to west); with regularly horizontal aligned deposits in mortar, pavement and polychromatic mosaics; and a necropolis consisting of twelve graves, located in an area defined by granite slabs and/or brick coverage. These individual spaces were occupied successively over a 2000-year period.
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.