Esslingen Castle has been the city’s most recognizable landmark for almost 700 years. It was built originally in the 13th century and enhanced in 1519-1531. Preserved elements in the Old Town of the corresponding city wall include the Schelztor, the Pliensauturm and the Wolfstor. The castle is open to the public, and the famous Dicke Turm has also recently reopened for visits by guided tours. The ascent of more than 300 steps rewards visitors with a unique view over the city.
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.