filler edit Rijeka[a] is the principal seaport and the third-largest city in Croatia. It is located in Primorje-Gorski Kotar County on Kvarner Bay, an inlet of the Adriatic Sea and in 2021 had a population of 107,964 inhabitants.[5] Historically, because of its strategic position and its excellent deep-water port, the city was fiercely contested, especially between the Holy Roman Empire, the Republic of Venice, the Kingdom of Italy and Yugoslavia, changing rulers and demographics many times over