The town's landmark attraction, this 88m-high, 475m-long chunk of multihued limestone has inspired descriptive entries in travel journals dating back to Samuel de Champlain's captain's log of 1603. It is accessible from the mainland only by boat, but it's dangerous to try to go ashore on this fragile natural wonder. Île Bonaventure cruises include a journey around the rock with commentary on its history and folklore.
Signs warning of falling rocks should be taken seriously: each year, some 300,000 tons of rock debris detach from the big rock. There used to be two holes in it, but one arch collapsed in 1845; in 2003, 100,000kg of debris fell at once.