The building hosting the contemporary Astronomical Centre Rijeka on the ridge of the Sveti Križ hill was constructed in 1941 as a military fortress for the Italian army in WWII. No longer serving its military purpose, the fortress has been adapted to modern conditions of the astronomy centre and today it is an attractive edifice surrounded by forest and lush landscape that create a peaceful setting.

As a result of support of the City of Rijeka and upon initiative of the Academic Astronomical Society Rijeka and the Association of Technological Culture, a telescope and a rotating dome were installed in 2001, an act which marked the beginning of the first astronomy observatory in Rijeka.

In 2004, a group of astronomy enthusiasts came up with the idea of transforming the observatory into the astronomy centre. With the support of the city government and vision of the project team the idea was put into practice.

Astronomy Centre Rijeka was formed by interpolating the new planetarium into the existing observatory fortress. Such a solution carries a symbolic meaning, too. The observatory with the telescope is set within the dome (a real image of the universe) and separated from planetarium set in the geometric shape of a polyhedron (a simulated image of the universe). Both the observatory and the planetarium are facilities indispensable for better understanding of the astronomy and the world that surrounds us in its infinite distances.

The planetarium displays a simulated image of space thanks to the state-of-the-art digital technology. The theatre has 50 seats with vertical axis providing the best possible experience during projections of the sky and sky objects on the 8m diameter dome.

Digital system of projectors and computer installation make it possible to experience transmission of accurate images of universe visible from the observatory telescope. This is particularly useful for observing attractive astronomical occurrences, such as Solar or Moon eclipse, meteor showers or transits of sky objects.