As it is often the case with signs for petrol stations, it is located a few kilometres away from the petrol pumps themselves 1. In this case one had to drive for another five kilometres before reaching Shell's forecourt in Saint-Genis-de-Saintonge.
This particular design for the Shell logo, with the yellow shell on a red square rather than with a red outline only, was used between 1961 and 1971.
Nowadays there is still a petrol station about five kilometres further south but it is part of the network of one of Shell's competitors, Total.
This ghost sign was painted over an earlier, and wider, one with a white background but it is not possible to tell what was advertised there.
1: for another example, click see another here.
Location: D 137, Belluire, Charente-Maritime / Pictures taken in 2012