The Astronomical Centre Rijeka sits on Sveti Križ hill, above the eastern side of the city, in a former military position turned science venue. It combines an observatory with a digital planetarium, which makes it more than a weather-dependent telescope stop; there is usually something to see even when the sky is not cooperating.
Come for the planetarium shows, but leave time for the terrace. The hill gives a wide look over Rijeka, the port, and Kvarner Bay, and the trip out here changes the city from a tight harbour grid into a place folded into steep coastal terrain. It is a good fit for families, science-minded travellers, or anyone who has already done the central sights and wants a different angle on Rijeka.