The first lighthouse on Rocher aux Oiseaux was built in 1871. It was a wooden tower with a total height of 15 metres. Today's lighthouse was built in 1967. It is an hexagonal reinforced concrete tower topped by an octagonal lantern compartment. The lighthouse on Rocher aux Oiseaux is in a key location: not only does it signals the northern limit of the shallow waters surrounding Les Îles, but it also marks the presence of a dangerous rock formation isolated in the middle of the Gulf of St. Lawrence. The lighthouse is often nicknamed "the sentinel of the Gulf".
Previously, the lighthouse on Rocher aux Oiseaux was only accessible by a staircase that allowed to climb the 30 meters cliff. Several lighthouse keepers succeeded one another, living in total solitude, until its automation in 1988. Although completely abandoned after the automation, several buildings, including the lighthouse keeper's house, a building housing a generator, the building housing the foghorn and a telecommunications tower remained in place for a few decades before being dismantled at the end of 2020. Some artefacts from this mythical place in the history of Les Îles have been preserved by the Musée de la Mer before the demolition.