If you want to explore the history of St Malo without all the walking, take the Vagabond, a small train that travels through the streets of Intra-Muros on a 30 minute tour.
Boarding by the tourist office opposite Port Saint-Vincent, you'll learn much from the audio commentary. Find out all about the bay of St Malo and the corsairs and the French East India Company that were based here in the 16th and 17th centuries. The commentary also covers the history of the catheral, the rebuilding of the town after the Second World War and why the inhabitants of St Malo itself consider themselves unique as Malouins - distinct even from Bretons!