Jura

Jura, a range of mountains of a peculiar limestone formation, oolitic in composition, and generally called Jurassic, which extends from the angle formed by the Rhone and the Ain, in a north-easterly direction (with a gradually declining elevation) for more than 450 miles, to the upper course of the Main. But it is usual to restrict the name to the ranges that lie along the frontier of Switzerland and France—mainly in the departments of Doubs, Jura, and Ain. These constitute a plateau about 155 miles long by 40 wide, with an average height of 2000 to 2500 feet. The loftiest peaks are Reculet (5643 feet), Crêt de la Neige (2653), Mont Tendre (5512), and Dôle (5507). The eastern face is much steeper than the western. The ranges are broken by numerous transverse gorges or 'cluses.' Many roads and railways traverse the chains, some of them of great strategic importance. Limestone caves are numerous, and they abound in magnificent stalactites and in the bones of extinct animals. Some rivers of considerable size sink into the ground and reappear after some distance, as the Orbe, the Doubs, and the Creuse. Fine pine-forests are a characteristic feature of the scenery.