Les Alleux is some 30 km (19 mi) east of Rethel and 10 km (6.2 mi) north of Vouziers. The commune can be accessed by the D977 road from Vouziers in the south passing through the commune to the east of the village and continuing to Le Chesne in the north. Access to the village is by the D23 road from Voncq in the west and continuing north to join the D977 inside the commune. Most of the east and west of the commune are forested with the central part farmland.[3]
An unnamed stream rises south of the village and flows north-west to join the Ruisseau des Graquinettes just west of the commune.[3]
Gules, a chevron of Or accompanied in chief by two arrows of Argent in pale and in base by a crescent the same; in chief overall Azure charged with three mullets of Or.