The Mezquita was built from a visigothic basilica from the 5th century, reusing its materials, and is one of the few surviving Spanish rural mosques.
It is an oddly-shaped building, made of brick and stone in a trapezoid shape, probably because of the hilly terrain. The oration room has 5 naves, whose arches, like in the Mezquita in Cordoba, are perpendicular to Qibla. The central nave is wider than the 2 nearby, which are in turn wider than the 2 outer naves. The Mihrab has lost its paint, and looks quite archaic; only the brick and stone is visible. In the oration room, 16 undated tombs were found.
When Spain became Christian, many changes were made, including the addition of a central axis in accordance with the new religion. The old door and the North flank were also reconstructed. Despite these changes, the whole building still retains a rustic charm.
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.