This oldest native Croatian city on the Adriatic is located in the most protected natural harbour, in the centre of the eastern coast of the Adriatic Sea. This is probably in the same place where some of the original Croatian settlers first saw the blue sea. Sibenik's narrow winding streets, stony houses, many staircases and the remains of the city walls give it a romantic Mediterranean atmosphere. The St. Jacob's Cathedral is the most famous building in Sibenik. It was constructed over a period of a century, and is testimony to the determination, sacrifice and belief of the generations of inhabitants of Sibenik. By many things it is unique not only in Croatian architecture, but in European architecture as well. It is entirely built of stone, no other material was used. It is unique in its brave structure of stone slabs and ribs, with no binding material; it is also unique among renaissance churches in its trefoil front facade. Finally, it is unique in the harmony of its architecture.