Circuit de la Sarthe is the track the 24 Heures du Mans race is held on. There are 2 versions of the track in GT4, the present chicaned one, and the older one without chicanes, I believe the older one is the layout from 1987-1989.
However, it looks like the hill at the end of the straight is like it is today.
But there is a good explanation for that.
Since this should be PD's first time at Le Sarthe, the hill was redone. So instead of trying to recreate the hill for both versions of the track, they did it as it is today.