 In the interior the boundary fell between Casinum and Teanum Sidicinum, at about the 100th milestone of the Via Latina, a fact which led later to the jurisdiction of the Roman courts being extended on every side to the 100th mile from the city, and to this being the limit beyond which banishment from Rome was considered to begin.Though the Apennines comprised within the boundaries of Latium do not rise to a height approaching that of the loftiest summits of the central range, they attain to a considerable altitude, and form steep and rugged mountain masses from 4,000 to 5,000 ft. high.They are traversed by three principal valleys