The highlight of Louisbourg Harbour is a 64 gun French ship, tentatively identified as the Célèbre. This site is located a few hundred yards from the imposing architecture of the town's reconstructed 18th-century buildings. Occasionally a cannon shot is heard or perhaps musket fire. An 18th-century fishing crew in a chaloupe sails past, hand-lining for cod. The setting is unique and quite unforgettable.

The Célèbre lies in 7 meters of water and has undergone little change since its discovery in 1961. Usually covered with long strings of kelp, the Célèbre is carefully cleaned each spring to reveal a wreck site over 50 m long.

The most conspicious features are the cannons: 33 large, formidable guns, some over 3 meters long and weighing approximately 2½ tons. The overall barrel lengths indicate calibre sizes representative of a 64-gun ship. The cannons are heavily corroded and, although appearing quite massive and indestructable, they are in fact quite fragile. An accidental bump into a cannon by a diver with boyance problems could cause a crack in the outer layer of the corrosion products, followed by a stream of escaping bubbles indicating its unstable condition. In other instances, simply swimming too close can cause serious damage. For this reason a policy of "look, but don't touch" is closely monitored by the accompanying tour operator.

Structurally, most of the ship's hull was burned during the 1758 siege and little remains to be seen. However, the large stump of the main mast, over 1 meter in diameter, is still locked in place by the surrounding mast-step timbers. This once majestic mast would have towered over 50 meters above the upper gun deck.

The bottoms of the two bilge pumps are aligned along one side of the mast. The shot locker, long since emptied in battle, is clearly outlined forward of the mast. Nearby is a meter-long cylinder, the working barrel from one of the ship's bilge pumps. This single artifact, because of standard lengths at the various shipyards, identified the wreck as being built at either Brest or Toulon. Of the two 64-gun ships sunk at Louisbourg, the Capricieux was built at Rochefort and the Célèbre was built at Brest.

Other artifacts scattered around the wreck site include numerous cannon balls and bar shot, a small anchor, brass and wooden pulley shards, iron structural supports, strips of lead from the ship's oven and a fire hearth.