Route des Crêtes

The crest road which connects the town of La Ciotat to that of Cassis, runs in laces on the edge of the cliffs of Soubeyran (394 m), which are the highest seaside cliffs in France. The view is spectacular both in terms of the landscapes seen at the top of these cliffs and the road itself which evolves in pretty landscapes presenting a remarkable geology. This road is closed on very strong mistral days. This powerful wind can indeed be very intense at this height.

Impressive journey on the D 141, the Route des Crêtes, between La Ciotat and Cassis.
I didn't cycle the entire route, but especially at the viewpoint I had great views of the sea, the cliffs and the landscape in the hinterland.
More info: de.wikipedia.org/wiki/Corniche_des_Cr%C3%AAtes

The Route des Crêtes which links Cassis to La Ciotat offers breathtaking views of the Mediterranean Sea and the Calanques massif. The steeply sloping road climbs up to Cap Canaille, then winds along the ledge of the Soubeyran cliffs (394 m), the highest cliffs in France.
(NB: The name Route des Crêtes is used in many regions to designate a mountain tourist route offering many points of view.)
fr.wikipedia.org/wiki/Route_des_Cr%C3%AAtes#Provence

The route des Crêtes is a magnificent ride between Cassis and La Ciotat, with 360 degree views over some of the most superb scenery in Provence all along the way.
This 15 km / 9 mile stretch of road will take about half an hour by car and about an hour by bicycle - if you don't stop ...
marvellous-provence.com/activities-and-sports/drives-and-rides/road/route-des-cretes
laciotat.info/loisirs/route-des-cretes
Warning: road might close in bad weather