 Haute-Marne is part of the region of Grand Est and is surrounded by the departments of Meuse, Vosges, Haute-Saône, Côte-d'Or, Aube, and Marne.The highest mountain is Haut-du-Sac, in the Langres Plateau, in the southwest of the department, which rises to a height of 516 m (1,693 feet).The lowest points at 117m are found on the plains of Perthois and Der.