Fagaras Mountains offer the most challenging climbing routes as well as the most breathtaking panoramas. Lighter trails are available in Retezat, Apuseni, and the Piatra Craiului Mountains; but the most popular hiking destinations are Sinaia, Busteni, Zarnesti, and Petrosani. Mountains occupy one-third of the country's territory.
Romania also boasts 400 natural parks and reserves worth being explored. Standard hiking season runs from April through October, yet the most challenging trails and highest summits are accessible from early July.