The Chitwan Valley (Nepali: चितवन उपत्यका) is an Inner Terai valley in the south of Nepal, encompassing the districts of Makwanpur, Chitwan and Nawalpur. The valley is part of the Terai-Duar savanna and grasslands ecoregion of about 150 km (93 mi) length and 30–48 km (19–30 mi) width. Major cities are Hetauda and Ratnanagar in the easternmost part of the valley, Narayangarh and Bharatpur in its central part.