The Olt is a river in Romania. It is 615 km (382 mi) long, and its basin area is 24,050 km2 (9,290 sq mi). It is the longest river flowing exclusively through Romania. Its average discharge at the mouth is 174 m3/s (6,100 cu ft/s). It originates in the Hășmaș Mountains of the eastern Carpathian Mountains, near Bălan, rising close to the headwaters of the river Mureș. The Olt flows through the Romanian counties of Harghita, Covasna, Brașov, Sibiu, Vâlcea, and Olt. The river was known as Alutus or Aluta in Roman antiquity. Olt County and the historical province of Oltenia are named after the river.

The Carpathian Mountains or Carpathians are a range of mountains forming an arc across Central Europe. Roughly 1,500 km (930 mi) long, it is the third-longest European mountain range after the Urals at 2,500 km (1,600 mi) and the Scandinavian Mountains at 1,700 km (1,100 mi). The range stretches from the far eastern Czech Republic (3%) and Austria (1%) in the northwest through Slovakia (21%), Poland (10%), Ukraine (10%), Romania (50%) to Serbia (5%) in the south. The highest range within the Carpathians is known as the Tatra mountains in Poland and Slovakia, where the highest peaks exceed 2,600 m (8,500 ft). The second-highest range is the Southern Carpathians in Romania, where the highest peaks range between 2,500 m (8,200 ft) and 2,550 m (8,370 ft).