There are two routes to Noirmoutier Island, Vendee, France from the mainland; a modern bridge and a road at sea level. The bridge is just a short span at the southern tip of the island, and just a few hundred metres long; whereas the original road passage on the eastern side of the island is several miles across open sea to the island; and apart from a three hours window at low tide is submersed under water.
For practicality, the bridge is the obvious choice, but at low tide the French love queueing up in their cars to make this treacherous road journey; I guess just for fun, and the experience. On the mainland there is parking and several café’s where you can park up at low tide to have a bite to eat and a drink while you watch the fun.
For our part we always used the bridge when getting to and from the island, but we had to navigate there using an atlas as our TomTom (satnav) always insisted on trying to take us across the impassable road crossing; even when our car was just one side or the other of the bridge and in spite of the fact that the bridge was showing up as a valid road on the TomTom maps. We’ve always felt our TomTom has attitude, and this is a prime example.