Archaeological research carried out over a couple of last decades in the territory of the city of Rijeka confirmed the existence of a fortified enclosure within which there was a military headquarters or the Principia which represented a separate urban complex. The finds discovered during protective archaeological research carried out in April 2004, confirmed once again an exceptional importance of this location.
During 2006 and 2007, in cooperation with the City Department of Culture and the City Department of Development, Urban Planning, Ecology and Land Administration a tendering procedure and other preparatory works and preliminary activities were conducted, necessary to carry out protective archaeological research of this site so that the Principia in Rijeka may be confirmed as an archaeological monument of a high category.
In September 2008, an architectural competition was published for the elaboration of a conceptual architectonic solution relating to the refurbishment of the Principia in the Old Town. The work of the architects Nenad Fabijanić and Sonja Tadej won the first prize. In this way, the City of Rijeka as investor received a quality base for preparing further project documentation necessary to refurbish this city square. Also, preparatory works were completed so that the book titled “Riječki principij” dedicated to conducted archaeological research in 2007 could be printed.
Works for the refurbishment of the Archaeological park were carried out in the period from 2013 to 2014. In this period detailed architectural surveying took place and archival, conservation and constructive research of the building close to the zone of the archaeological park, in accordance with the request of the competent Conservation Department, which performance was ordered by the City of Rijeka.
The Archaeological park was inaugurated in February 2014.