Seaside (near from Nantes) by chess_machine
Within an hour from Nantes, you have access to several beaches, very different. Interested by Britanny, you can visit the superb Golfe du Morbihan (south of Britanny), which capital is Vannes. Interested by fashion beach, with trendy clubbing, boutiques and 20 year old beauties, La Baule is the place to go. Fond of islands, you can go to Noirmoutier, Belle-Ile or l'Ile d'Yeu. If you dont want to go too far away and want to find a beach within 45 minutes, then go to Saint Brevin or Pornic. Well, there are more than 20 beaches within an hour from Nantes so you have plenty of different choices.
If interested, check my travel pages on Noirmoutier, La Baule, Saint Nazaire.