Grand Bé is a tidal island reachable on foot from Saint-Malo at low tide, a short walk across the sand from the beach below the ramparts. The island is dominated by the tomb of the Romantic writer Chateaubriand, which occupies the highest point and commands a view of the open sea and the coast in both directions. The atmosphere is solitary and atmospheric — especially at dusk when the tide is coming in and the causeway begins to disappear.
The island should only be visited when the tide is clearly going out, never when it is coming in. The tidal range here can be over 12 metres, and the causeway floods quickly. There are signs warning of this, and the local lighthouse posts tide schedules. The walk to the island and back takes about 30 minutes; allow more time if the sand is soft. On the adjacent Petit Bé stands another small fort, also accessible at low tide.