The "Museum Collection of Plastic rocks" of the MI City Museum of Negotino - Negotino, is composed of 140 models of archaeological items dating from the 2nd century BC until the 6th century AD, collected by the realization of the project "Collection of plastic rocks", whereby the items were found as random findings discovered by the population during cultivation of agricultural land and reported in the museum, and some were also found in archaeological research at certain sites in the municipality. The collection contains objects from the ancient period and epigraphic monuments as part of the architectural decorative plastics and some of them are exhibited and placed in the lapidarium of the MI City Museum of Negotino. In the lapidarium among the exhibits there are bases, columns, capitals, impost capitals, fragments of architrave beams, fragments of tympanums, sepulchral arae, sarcophagus-ossuary, testament plates and cult items – arae sacrificial altars. They differ among themselves according to their chronological and cultural affiliation, function, material, form and manner of use.

They describe several segments of the everyday life of the populations inhabiting the territory of the present day municipality, presenting the development of the spiritual and material culture presented through interesting notions of beliefs and customs, artistic understandings, trade and cultural ties, and the like. The epigraphic monuments - tombstones, which are part of the collection and are of a private character, are especially distinguished because they contain an inscription field in which the epitaphs written in Ancient Greek language mention the names of the deceased to whom they are addressed, as well as the names of the people who have erected the tombstones. Astrology and lunar symbols are also present on the stelae, which have the function of extending the message of the afterlife that is characteristic of this region.

The lapidarium, which is part of the museum collection of plastic rocks, possesses a sophisticated set of data and knowledge, which has an informative, educational, cultural and scientific function. The presented items in the archaeological exhibition together with the lapidarium in the yard of the MI City Museum of Negotino, represent the life of the population from the prehistory through the ancient period to the medieval period, which causes great interest and curiosity among visitors.