The Early Bronze Age site of RJ-2, located close to the coastal village of Ra's al-Jinz on the eastern Omani coast (Niyabat Ra's al-Hadd), was the focus of archaeological investigations for over two decades. The latest campaigns of excavation unearthed an architectural complex (Building XII) dated to the very end of the Umm an-Nar period (Final UaN, c.2100-2000, previously attested on site by poorly preserved remains. This paper presents the remains explored during the most recent fieldwork, focusing on the stratigraphic-structural sequence and the spatial layout. It also considers the transformations affecting structural evidence and material culture during this period, at both local and regional level, highlighting their significance for a comprehensive assessment of the last occupations related to the Early Bronze Age in south-eastern Arabia. The paper concludes by showing how the Final Umm an-Nar phase represents an age of substantial socio-cultural innovations, which most likely shaped the transition towards the following Wadi Suq period.