Royan's central market is a shell of thin concrete, built in 1956 with a sweeping, pillar-free vault and skylight at the centre. It is both a working food market and one of the town's clearest examples of 1950s optimism.
Go in the morning, when the stalls are busy and the building is doing what it was made for. The structure is more interesting with fish, fruit and local shoppers under it than as an empty monument.