These are the world famous calanques, which signifies "deep narrow creeks" Leave Apt on the 943 until you reach Cadenet, continue along the D973 towards Pertuis, and then head for Aix on the D556.
Visit Aix-en-Provence, which is certain to charm you.
Then take the Motorway (autoroute A8) in direction of Nice, after the toll booths, head for Toulon on the A52, and exit at La Ciotat. Visit the village and the port, and then follow the tourist road towards Cassis, along the crests, from where you will enjoy a number of breathtaking views of La Ciotat first and then Cassis.
Cassis, the port and especially the Calanques, either on a boat of on the walking paths. Then you can head for Marseille on the D559 and going through the "col de la Gineste".
Visit Marseille, the old Port (le Vieux Port), the Canebière and Notre Dame de la Garde, the Church dominating the city. Return to Apt on the A7, exit at Cavaillon, the capital of Melons, which, if it is not too late in the day, is a pleasure to visit.