Mehdishahr (Persian: مهدی‌شهر‎, also Romanized as Mehdīshahr;[2] formerly, Sang-e Sar (Persian: [3] سَنگِ سَر‎, also Romanized as Sang-i-Sar[4] and Sangsar)[5] is a city and capital of Mehdishahr County, Semnan Province, Iran.