ALTENSTEIN  , a

castle upon a rocky mountain in Saxe-Meiningen, on the south-western slope of the Thuringerwald, not far from Eisenach . It is the summer residence of the dukes of Meiningen, and is surrounded by a noble park, which contains, among other objects of interest, a remarkable under-ground cavern, 500 ft. long, through which flows a large and rapid stream . Boniface, the apostle of the Germans, lived and preached at Altenstein in 724; and near by is the place where, in 1521, Luther was seized, by the order of the elector Frederick the Wise, to be carried off to the Wartburg . An old beech called " Luther's tree," which tradition connected with the reformer, was blown down in 1841, and a small monument now stands in its place .