Antras is located some 25 km south-east ofSaint-Gaudens, 20 km north-east ofBagneres-de-Luchon, and only 1 km from the Spanish border. It was part of the former province ofCouserans in the Biros Valley. No district roads or highways pass through the commune and the only access to the village is by a mountain road (the Route d'Antras) from the D4 road atSentein. There are few roads in the commune with some mountain tracks and unformed roads. The commune is mountainous and heavily forested.[3]
TheRuisseau d'Antras flows from the commune down to Sentein where it joins theLez which continues toSaint-Girons where it joins theSalat river.[3]