Significant parts of the city walls of Piran remain well-preserved. Piran's three walls were built in response to the city's expansion. The first wall was built in the 7th century, separating the town into four streets. The first wall can be seen in the old part of the town. The wall was moved south-west when new streets were built. The fortification wall, which was built along the southern coast of the town, hasn't changed much since it was first built.
In the final phases of expansion between 1470 and 1538, the second fortification wall was built to protect the peninsula during construction. It protected the MarÄana quarter. The biggest part was built when the use of gunpowder became frequent.
The third wall is almost completely intact. Its northern part is accessible while the southern wall's floors and stairs are missing or are under reconstruction. Between them a gap opened where the wall collapsed. A small portion of the third wall is next to the rectory, facing north. A tower viewer is located in one of the towers.Seven city entrances or gates remain preserved.
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.