Forming a natural border between the regions of Champagne and Lorraine, the Argonne is a compact region, 65 km long and 15 km wide, slashed with deep valleys formed by off-shoots of the Aire and Aisne rivers. The forest of the Argonne served as a wooded barrier between the rival bishoprics of Champagne and Lorraine and was home to a number of abbeys and priories.
