It’s one of France’s most iconic images: the slender spires, stout ramparts and rocky outcrops of Mont St-Michel rising dramatically from the sea – or towering over slick, shimmering sands laid bare by the receding tide. Despite vast numbers of tourists, both the rock-top abbey and the narrow alleys below still manage to transport visitors back to the Middle Ages.

The bay around Mont St-Michel is famed for having Europe’s highest tidal variations; the difference between low and high tides – only about six hours apart – can reach an astonishing 15m. The Mont is only completely surrounded by the sea every month or two, when the tidal coefficient is above 100 and high tide is above 14m (check online before you go, if this is what you want to see). Regardless of the time of year, the waters sweep in at an astonishing clip, said to be as fast as a galloping horse.