I like the idea of surprise made to your wife.I'm happy to make you discover our country and give you some ideas , respecting your priorities : relaxing, hiking and beaches.I have searched on a lot of sites and guides and offers you some options , with discoveries of wilderness and unspoilt,with picturesque villages , canyons and creeks.
First, I suggest you discover the Ardèche and its gorges.L Ardèche is a department with many villages classified "historical".These are medieval villages,having been awarded the " village character.Most have a medieval castle , cobbed streets,stone houses , ramparts encircling villages and numerous Romanesque chapel
The most beautiful picturesque villages are circled in green.
http://www.experienceardeche.com/page/places_interest/63
http://en.ardeche-guide.com/villages-outstanding-character
The Ardèche is south of Lyon, 150 km, to Marseille by "Autoroute du Sud"(HW A 7) .Take exit 17 Montélimar North direction Montelimar / Le Teil by N7, then N107 to Le Teil , to visit the villages classified.
Then De Vallon Pont D'arc, which is the top of the Ardèche, with discovery of the gorges of Ardeche, many walking trails.Vallon Pont d'Arc is the starting point for canoé/kayak.There are many beaches within walking distance.May is the ideal time for climate,vegetation and calm.It's the crowds in summe
Hiking trails
https://www.tripadvisor.com/ShowTop...he-Vallon_Pont_d_Arc_Ardeche_Rhone_Alpes.html
http://www.ot-pays-ruomsois.com/en/les-gorges-de-l-ardeche/index.php
beaches
https://www.tripadvisor.com/ShowTop...he-Vallon_Pont_d_Arc_Ardeche_Rhone_Alpes.html
http://www.aubenas-vals.com/coins-de-baignade-en-ardeche/
You can find all the informations and maps at the tourist office in Vallon Pont D'arc
http://www.vallon-pont-darc.com/#close
also the descent of the gorges of Ardeche in canoe / kayak. (see the website of the tourist office)
http://www.canoe-ardeche.com/indexa.html
I advise you the Michelin map N° 331 (Ardèche /Pays de Loire). 1/150000 .you should find it on Amazon.
if you don't have overdose the canyons, trails or beaches, the sea is 170kms.I suggest you visit Cassis to La Ciotat.
To avoid the black circle, which is a highly industrialized area.

Cassis is a little port, departure point for many hikes to the creeks, so that you can visit by boat.These creeks are protected.These are heavenly places.Cassis is also famous for its wine(rosé and white).
What's more pleasant to sip a chilled rosé with a view breathtaking with his beloved.!
http://www.marvellous-provence.com/other-places/sights-and-attractions/calanques/cassis
http://mikestravelguide.com/what-to-see-and-do-in-cassis/
to do absolutely: the ridge road (la route des crêtes) of Cassis to La Ciotat 15 kms of view from cliffs offering a breathtaking panorama of Cassis,its creeks and the sea infinity.
I advise you the Michelin map Bouche du Rhone / VarN°340 1/150000(Amazon)
for the return to Lyon, you can leave the HW A7 after Salon de Provence, to the "Parc Naturel Régional du Luberon,"to discover other classified villages of this region.The best being Gordes and Roussillon.
http://www.provenceweb.fr/e/vaucluse/gordes/gordes.htm
http://www.marvellous-provence.com/...of-the-luberon/roussillon-and-the-ochre-trail
http://www.planetware.com/luberon/parc-regional-du-luberon-f-az-plu.htm
I know the South region of Cassis and the Luberon. I loved the unique and unspoiled beauty of this region,the festive atmosphere and the warm hospitality of Provence.
The last year, I left Ardèche with lots of projects, and ... unfortunately, a broken foot has limited rides.
Thanks to you, I got a roadbook for an upcoming trip.
If you need additional informations,....with pleasure
catherine