Târgu Mureș is the seat of Mureș County in the historical region of Transylvania, Romania. It is the 16th-largest city in Romania, with 11…Târgu Mureș is the seat of Mureș County in the historical region of Transylvania, Romania. It is the 16th-largest city in Romania, with 116,033 inhabitants as of the 2021 census. It lies on the Mureș River, the second-longest river in Romania.