At Agen we took the N21 south to Auch.
Ca 10 kilometres before Auch, near to Preignan, we turned to the right direction Roquelaure, D272.
Beware, the route is a bid cluttered, you have to drive around a restaurant positioned at a river.
Then the D272 goes trough a village, bends to the left, runs along a housing estate and turns right.
Nearly immediately you see the beacon at the LHS of the road.