Île Besnard, Tidal island in Saint-Coulomb, France.

Île Besnard is a low, rocky landmass at the entrance of the Rothéneuf harbour, its shoreline built of grey and brown stone with deep vertical cracks and overhangs. Above the rocks, low green grass and dry yellowish-brown vegetation cover a gently uneven surface that slopes up to a broad, flatter top. A single small white building with a dark roof, the former semaphore, stands near the water's edge on the far side, among a few low bushes and trees.

The island's summit holds a former semaphore built around 1862; the State assigned it to the Conservatoire de l'espace littoral. The site is now owned by the Ille-et-Vilaine department, which manages and maintains this protected natural area. A sand tongue formed by the Chevrets dunes, the tombolo, now links it to Pointe du Meinga.

The name Besnard refers to the island's position at the mouth of the Rothéneuf haven, which its cliffs shelter. Across the water stand two islets, Petit Chevret and Grand Chevret, where crested cormorants, terns and gulls can be watched. The site is now a protected natural area owned and maintained by the Ille-et-Vilaine department.

Access to the island depends entirely on tide schedules, which change daily. Visitors should check local information before planning their visit and time their exploration around water levels.

A semaphore tower built in 1862 crowns the summit and is now managed by the Coastal Conservation Authority. This historic structure serves as a vantage point over the bay and forms part of the protected natural site.