Rijeka is the administrative and cultural centre of the Primorje-Gorski kotar County and the third largest city in Croatia with regard to the number of inhabitants. The city is situated along the course of Rječina River and nearby numerous streams. It lies on abundant sources and confluences. Like numerous cities in the world, Rijeka carries the symbol of water in its name. There is little of tourist interest in Rijeka, since sadly much of the finest architecture was flattened during World War II. The unusual circular 17th century cathedral of St Vitus is worth a visit if you are here. Another unusual attraction that will probably appeal to those with an interest in military history is a torpedo factory where, during the days of Austro-Hungarian rule, the first naval torpedo was tested in 1866. Lovers of exercise will appreciate the climb to the top of the hill of Trsat which overlooks the town, where there is a restored mediaeval castle as well as the important church of Our Lady of Trsat and a nearby Franciscan monastery. It's worth a walk along the main pedestrian street, Kozo. There is also a quite remarkable building of the National Theatre (Hrvatsko narodno kazalište) and 3 buildings of the covered market nearby. A short bus ride to Opatija is worth an effort. Get off at Volosko and have a walk towards Opatija along the coastal promenade (obalno šetalište Franje Josipa I).