The Île de Batz lies just a few hundred metres off Roscoff harbour, a 15-minute boat ride on the regular ferry. It's a low, green island of about 500 inhabitants, crossed by sandy lanes and fringed with beaches that are sheltered enough for swimming even in early summer.
The Jardin Georges Delaselle on the island is a remarkable exotic garden created at the end of the 19th century, with hundreds of palm species from around the world growing in the open air. The island's lighthouse at the western tip is open to visitors — the climb gives sweeping views across the Breton coast and out to sea. Bikes are available for rent from the ferry landing.