The western part of the strait leads northwest from the northern end of the Magdalena Channel to the strait's Pacific entrance. This is flanked on the south by Capitán Aracena Island, Clarence Island, Santa Inés Island, Desolación Island (Cabo Pilar), and other smaller islands, and on the north by Brunswick Peninsula, Riesco Island, Muñoz Gamero Peninsula, Manuel Rodriguez Island, and other minor islands of the Queen Adelaide Archipelago. Two narrow channels connect the strait with Seno Otway and Seno Skyring.