The region lies south of the Vindhya Range, and consists of two portions of the Narmada and Tapti river valleys, separated by a section of the Satpura Range, about 15 miles (24 km) in breadth. On the highest peak, about 800 ft (244 m) above the plain and 1800 ft (549 m) above sea-level, stands the fortress of Asirgarh, commanding a pass which has for centuries been the chief highway between Upper India and the Deccan.