NIEDERLAHNSTEIN, a town of Germany, in the Prussian province of Hesse-Nassau, situated on the right bank of the Rhine at the confluence of Lahn, 3 m. S.E. from Coblenz by the railway to Ems, and at the junction of lines to Hochheim and Cologne. Pop. (1905) 4351. It has two Roman Catholic churches. The chief industries are the making of machinery and shipbuilding. Niederlahnstein obtained civic rights in 1332, and was until 1803 on the territory of the electors of Trier. Here on the 1st of January 1814 a part of the Russian army crossed the Rhine. In the vicinity are the Johanniskirche, a Romanesque church restored in 1857, and the Allerheiligenberg, whereon stands a chapel, once a famous place of pilgrimage.