Ploesti (or Ploiești) is the county seat of Prahova County and lies in the historical region of Wallachia, Romania. The city is located north of Bucharest. In the first half of the 20th century, Ploesti had a thriving petroleum industry. During World War II, Ploesti provided a substantial amount of oil to Germany, and so the city was targeted by the Allies for aerial bombardment on several occasions, the most notable of these being in 1943, with Operation Tidal Wave.