La Porte du Der () is a commune in the Haute-Marne department of northeastern France. The commune was established on 1 January 2016 and consists of the former communes of Montier-en-Der and Robert-Magny.Arrêté préfectoral 29 December 2015
Population Population data refer to the commune in its geography as of January 2025.
See also Communes of the Haute-Marne department
References