This 4 stotinki stamp from the People’s Republic of Bulgaria (Н.Р. България) depicts the V. Kolarov Dam, a major hydro-engineering project named after Bulgarian political leader Vasil Kolarov. Issued during the socialist era, the stamp reflects the period’s emphasis on industrial progress and large-scale infrastructure achievements. The design shows the dam structure against a backdrop of reservoir waters and surrounding landscape. Such issues are of interest to collectors focusing on Eastern European post-war development, engineering, and socialist themes.