If you are going by car from Rijeka to south Croatia, you'll pass near by Velebit National Park (after Senj, there is roadsigns to Krasno...also nice place for short stop and try famous cheese). Ask for direction to Kuterevo (around 100 km from Rijeka). Visit this amazing shelter and you'll see young bears and people who take care about them. There are options to stay for night in village, ask people in bear shelter for direction.
Fuzine is small city, 750m above sea level in region called Gorski kotar, half hour drive from Rijeka in Zagreb direction. You can go there by bus or by car. Beautiful lake, small traditional houses, extreme clean nature and fresh air, charming in winter with snow, with some excellent restaurants offering local food.
Ucka is beautiful mountain near Rijeka (main photo was taken from my balcony) with highest peak Vojak (1401 m - second photo)
Part of the mountain is beautiful nature park with lots of possible activites you can be involved: mountain climbing, trekking, free climbing, paragliding and hang-gliding, mountain biking.
Ucka is nature border between Istra region and Kvarner region. You can reach top with car as well. On a clear day, view is amazing, you can see biggest Croatian islands (third photo) or beautiful Istra region from other side of mountain (fourth photo - not that good). Also, it's always better to go up after rain or north wind, you'll fill in your lungs better. Hike pats are very well designated so probably you cannot be lost. You can find some good restaurants on the way to top. Last photo was taken from Rijeka's port.
Kostrena is first small city after eastern exit of Rijeka. Don't be afraid when you see shipyard between this two cities. There is excellent place to walk next to the sea and enjoying nature and fresh clean air. You can go there by bus or taxi for relaxation but on weekends there are so many people walking along the promenade.
Check all photos attached. Photos are taken in winter. During summer here is nice beach (even so close to Rijeka city you can swim and belive me it's not that dirty as many people in Rijeka would tell you, of course, if you have more time, go to islands). Don't be afraid of heavy industry facilities. It's so common around Rijeka.
This 11 km promenade (called Lungo mare) from western part of Rijeka to Lovran via Volosko and Opatija is great way to relax and walk next to sea, old trees, old beautiful villas, specialy on sunny days. You can finish your walk in some Lovran or Opatija cafes and then go back to Rijeka with taxi or bus.
Check all photos attached with this tip.
Kastav, a town fortified by a town wall with nine defensive towers, was built on the ridge of Karst mountain (377 meters above sea level). It is situated very near Opatija (6 kilometres) and Rijeka (10 kilometres), only 20 kilometres from Rupa, the Croatio Slovenian border.
The history of Kastav is turbulent. Archeological discoveries confirm the presence of an Illyrian tribe of Japodi in 11th century B.C. on the site of today's town. After them the town was governed by the Romans, Ostrogoths, Greeks, Lombards and in the 7th century the Croatians moved to the place and stayed here till today.
Great for half-day trip. You can take bus No. 18 from Rijeka city centar and just walk around the city. There are five pics attached to this Tip so check them all.
They say Velebit is the most beautiful mountain in Croatia. I've been to North Velebit and it really looks fantastic. A very good thing (or a very bad thing) is that you can reach the top by car :-)
The view ... Rab, Cres, Lošinj, Plavnik, Grgur, Goli ... all of them in front of you... really nice.
If you're into hiking, climbing and that kind of stuff, you'll love Gorski kotar. Its just 20-30 km from Rijeka (depends on where exactly you're going).
Risnjak and Snjeznik are my favourite mountains in that area. It takes something like 2 hours to get to the top, but you won't regeret all that trouble once you see the view. When its very very clear, you can see all the way to Italy.