Rijeka is the administrative and cultural centre of the Primorje-Gorski kotar County and the third largest city and one of principal ports of Croatia. It sits at the estuary of Rječina river and has a long and interesting history, starting as a Roman military camp and being a strategic port for centuries, under various empires and states. Its location and history have made Rijeka a city very open to new people and experiences.
Take a walk in the old city center or along the breakwater, see the sights ranging from amazing views of Kvarner Bay to industrial heritage sites or just enjoy a cup of coffee or local cuisine (anything from barbecue to pizza to fresh seafood).
For more info, visit the official Rijeka tourist board website.