The nearest town on your map is probably Annot which is on the main
road between Nice and Digne. Peyresq and Annot are inthe Alpes de
Haute Provence department.
From Nice to Annot:
Take the RN202 from West
Nice towards Digne and stay on it, following the Var river, through
Puget-Theniers, Entrevaux and then to Annot. You can't go wrong.
From Digne to Annot:
Take the N85
towards Nice, turn onto the RN202 for Barrême, and continue to
Saint André-les-Alpes.
From Annot to Peyresq:
It's about 30
minutes' drive. Follow signs for St. André-des-Alpes until you
come to a small turn-off to Peyresq on the right. Then keep going as
far as you can. And that's Peyresq.
Here is a rough map. Click on it to see it at a larger scale.