Herceg Novi was founded (on a former small fishing village, existing since Roman Empire times) as a fortress in 1382 by first Bosnian King Stjepan Tvrtko I and was called Sveti Stefan or Castelnuovo. The Turks conquered Herceg Novi in 1482, and ruled for 200 years, until 1687. However, there was a short pause between 1538 and 1539 when it was held by the Spaniards before they were defeated in the Siege of Castelnuovo. Turkey ruled again until 1687, from then until 1797, the town was ruled by the Venetian Republic.
The Herceg Novi old town is amazing. It is on a fairly steep hill that leads all the way down to the sea. Wandering through the small stairways to the various plazas and fortresses is a many hour adventure. There are both Orthodox and Catholic churches that are well worth visiting.
Herceg Novi has two town squares, including the small, stone-paved Belavista (nice view), which is easy to get to from the main town square, Trg Nikole Đurkovića, once referred to as Salt Square, by walking up the stairs that lead through the town’s clock tower. Here, old stone buildings encircle the delightful church St. Arhangel Mihailo, a building unique in its architecture. This Orthodox Church is neo-Byzantine styled with Gothic and Romanesque details.
The Kanli Kula fortress dominating the old town doubles as an open-air theatre and is worth visiting mainly for the splendid views of the town and the Kotor bay.
The Spanjola fortress located higher up the mountain dates back to 16th century. Take a small street going upwards across from the Kanli Kula fortress.
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.