Roche à Caya is a small park on the island's western side, useful for a quiet walk, birdwatching, and views across the St. Lawrence. The marshy edge and open water make it one of the better places to stop if you are circling the island by bike.
It is not a major sight by itself, but it rounds out the island day nicely: a little wildness after the mills, orchards, and village road.