Osor is a picturesque town known as a museum town. The place has always been one of the leading urban centers of the islands of Losinj and Cres. Osor was built next to a canal with a movable bridge, which is also the only road connection between the two islands.
The Osor Canal was built with the aim of significantly shortening the voyage between Dalmatia and the northern Adriatic ports. The town was an important trade center until the 15th century, which became somewhat neglected due to the possibility of sailing on the open sea, plague and malaria. During the Roman period and the Middle Ages, Osor was surrounded by walls that have been preserved to this day. Above the walls stands the Church of St. Mary, which is known as the former city cathedral, and there is also a cemetery next to the church. The entrance to the city was decorated with a Venetian lion. In the historic center of the small town, the remains of its colorful past are visible, such as the bishop's palace, the cathedral with the bell tower, the forum, the loggia covered with a semicircular arch, where the town council used to meet. These buildings were built in the 15th and 16th centuries. They were completed during the period when the inhabitants closed themselves inside the walled city due to epidemics.
The Church of St. Gaudentius is located near the former city cathedral and the central square. It was built in the Gothic style in the 14th century. It was named after St. Gaudentius, who is known as the protector and bishop of Osor.