Câmpina is a city in Prahova County, Romania, north of the county seat Ploiești, located on the main route between Wallachia and Transylva…Câmpina is a city in Prahova County, Romania, north of the county seat Ploiești, located on the main route between Wallachia and Transylvania. Its existence is first attested in a document of 1503. It is situated in the historical region of Muntenia.