The exceptional ingenuity of Juraj Dalmatinac`s project is most evident in his solution for the baptistery. The steep terrain beneath the southern side of the apse made the accessibility to the baptistery extremely difficult. Therefore, in constructing the baptistery, and later on the sacristy, Master Juraj applied an original assembly system in which large stone slabs and blocks were brought together in such a way that the edge of one slab entered into a groove in the second slab, conquering the steep terrain.