You're spoilt for choice in every direction really. Of course, you have the obvious riviera locations along the coast, La Dramont near St Raphael was one of my favourite spots, along with various stopping points on the Moyenne Corniche between Nice and Monaco.
Into the mountains, pretty much anywhere in the Mercantour NP would be spectacular, around Madone de Fenestre is a lovely region, with great mountains and lakes. If you have chance, a trip over the border to Dolceacqua in Italy is a great day trip.
Also you are not far from Provence, and anywhere in the Luberon is fantastic, and you may be lucky and the lavender fields at Valensole may be in bloom. In a similar direction, the Gorges du Verdon are well worth a visit.