The island is still reachable at high tide thanks to a causeway unveiled in 2014, while low-tide visitors should be wary of wandering the sands – the tides come in very rapidly and there are quicksand dangers, so avoid the bay unless you're with an experienced guide.

Legend has it that the abbey was built in AD 708 on the orders of the archangel Michael, and it became a centre of pilgrimage and learning in the Middle Ages.

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