Ju'ra, a range of mountains extending from the angle formed by the Rhône and the Aar northeastward for over 450 miles. By Jura, however, is usually meant only the part along the frontiers of France and Switzerland. The highest peak is Reculet, 5,643 feet in height. The eastern slope is much steeper than the western one. The ranges are broken by many cross-gorges. Limestone caves are numerous, and abound in magnificent stalactites and in bones of extinct animals. Some good-sized rivers sink into the ground and reappear after some distance. The Jura Mountains are of a peculiar limestone formation, which geologists call Jurassic.
