St Nicholas’ Fortress in Šibenik: history and conservation research of building structures

U članku se donosi slijed svih zbivanja s tvrđavom sv. Nikole u Šibeniku od njezine izgradnje do danas, uz dataciju pojedinih očuvanih struktura. Nadalje, ranija su saznanja dopunjena novim arhivskim podacima, onima koji su prikupljeni analizom prethodne konzervatorske dokumentacije i onima koji su rezultat recentnih konzervatorsko-restauratorskih istraživanja Hrvatskog restauratorskog zavoda iz 2016. i 2017. godine. Uvažavajući vrednovanje svake pojedine faze tvrđave, osnovom za buduća postupanja predložena je njezina aktivna zaštita, s time da se i funkcija i predviđeni zahvati planiraju na način koji će osigurati zadržavanje cjelovitosti i identiteta tvrđave kao iznimno važnog kulturnog dobra te istovremeno doprinijeti očuvanju i nenarušavanju njezinih autentičnih povijesnih, umjetničkih i arhitektonskih vrijednosti.St Nicholas’ Fortress was based on a design by Giangirolamo Sanmicheli and built in the 1540s on the island of Ljuljevac, at the very entrance to the channel of St Anthony, near Šibenik. The idea for its construction was part of a complex defence system that fortified the city of Šibenik over the next few centuries, and the Republic of Venice secured one of its strategically most important cities along the eastern Adriatic during a period of frequent conflicts with the Ottomans. A thoughtful and innovative solution resulted in a harmoniously-constructed structure with a strong, simple volume with new elements, such as the so-called \u27pliers\u27, that would soon become the standard in Venetian fortification construction. Conservation research conducted by the Croatian Conservation Institute in 2016 included an analysis of previously-prepared conservation documentation, as well as archival research and a detailed analysis of the condition and damage to the fortress with conservation probes and laboratory tests performed on the material used for the construction. This helped determine the age of individual elements and phases of the fortress. The oldest, from the mid-16th century, is the most important one. Other phases relate to maintenance and changes to the outer mantle and terrace of the fortress. (Most of the work was carried out during Austrian rule in the second half of the 19th century.) The last phase includes conservation, in the last quarter of the 20th century, that aimed to rebuild the fortress, but at the same time introduced some major alterations to earlier structures. The biggest changes to date have occurred on the plateau, where the construction and demolition of individual buildings has resulted in an almost completely bare surface. Given that it is impossible to determine the details of individual phases, the current situation can be considered acceptable. Recent renovations prove that, in order to properly present this fortress, it is necessary to understand and respect the form, appearance and properties of the materials used during its construction. Throughout its history, the fortress has retained its original role as a fortification, which has certainly contributed to its preservation, and subsequent changes have not greatly affected its design or aesthetic characteristics. That landscape which has been preserved to this day, and the undeveloped St Anthony’s Channel, also contribute to the originality of the ambience as a whole, which should certainly be taken into account when planning the future use and organisation of the surrounding area. Respecting the characteristics of all factors, and primarily St Nicholas’ Fortress, it was necessary to determine starting points for its modern and functional use, with necessary but reversible modern interventions, all in order to ensure preservation of the integrity of its values