 Most of current Hunedoara was at that time a lush plain through which the Cerna river was meandering.The first blast furnace was built by 1603, followed by another four.The modern iron operations began at the foot of Saint Peter hill (Sanpetru), close to the most distant tower of the castle called Nebojša, (Serbian for "have no fear", a tower that was the furthest away from the castle in medieval times, to provide last refuge in the case of a siege; cf.