The Trsat Castle represents a strategically embossed lookout on a hill 138 meters above sea level dominating Rijeka. It was mentioned as a parochial center for the first time in 1288. At this same site, there was a Liburnian observation post from prehistoric times, used for monitoring the roads leading from the hinterland to the coast. This location served well to the Romans to establish their defense system, the so-called Liburnian limes, whose starting point was the Tarsatica fortress town – which was situated at the site of the today's Old City of Rijeka. It was the Frankopan dynasty based in Krk that fortified and enlarged the castle as it gave them a vantage point to protect their holdings. Trsat belonged to the Frankopans from the 13th through the 15th century and it then fell under Hapsburg rule. After the castle was damaged by an earthquake in 1750, Austrian field marshal Laval Nugent bought the ruins and restored them.

Opatija, with its tradition and appearance, stands out from other tourist towns because of her very colorful history and is also known under different names, such as "Old dame", "Pearl of the Adriatic" or "Queen of Tourism". Opatija is a great choice either during the summer or wintertime. Beautiful nature, parks, old villas, promenades, and beaches attract, for over 170 years, tourists from all over the world. It is known for fancy hotels, well-tended parks, and a unique promenade called "Lungomare".