Cap Trinite towers over 350 metres above the Saguenay River near the community of Riviere-Eternite, at the mouth of Baie Eternite. The cliff is composed primarily of granitic gneiss, a metamorphic rock forged under immense heat and pressure deep within the earth's crust. This is what gives Cap Trinite its exceptional hardness and its near-vertical profile, a wall so sheer that climbing routes on the face reach up to 350 metres. The cliff owes its existence to the Saguenay Graben, a large-scale geological fault system that runs through the region. Millions of years of tectonic activity along this fault line, combined with the scouring power of glaciers during the last Ice Age, carved the Saguenay into one of the longest and deepest fjords in the world. The fjord reaches depths of 270 metres, and its walls plunge almost as steeply below the waterline as they rise above it. Cap Trinite stands as the most dramatic expression of these forces, the place where geology made its boldest statement.

In 1878, Charles-Napoleon Robitaille, a merchant from the Saguenay region, became lost in a snowstorm while crossing the frozen fjord. As the blinding white closed around him and the temperature dropped, Robitaille made a vow: if he survived, he would erect a statue of the Virgin Mary on the great cliff. He lived. Three years later, the sculptor Louis Jobin carved a figure of the Virgin from white pine, standing 9 metres tall and sheathed in thin lead sheets to withstand the elements. The statue weighed three tons. Getting it to the ledge at 180 metres above the water required hauling the figure up the sheer cliff face in 14 separate pieces, then assembling it on a narrow natural platform barely wide enough to hold it. The feat demanded ropes, pulleys, and the coordinated labour of the community. On September 15, 1881, Notre-Dame-du-Saguenay was inaugurated on her precarious perch. At the time of its completion, it was the largest statue ever carved in North America.

For the Innu and other First Nations peoples who navigated the Saguenay for thousands of years before European contact, Cap Trinite was more than geology. The prominent capes along the fjord served as essential landmarks for travel and fishing, fixed points in a world of water and forest. The cliff's three-tiered form made it unmistakable even in fog or at great distance. The Quebec Commission de toponymie explains that the name Trinite, Trinity, derives directly from the cape's form: three equal caps arranged in echelon, like three superimposed stages. Later, the cliff became a cultural beacon for the entire Saguenay region. The painter Lucius O'Brien captured it in his 1880 work Sunrise over the Saguenay. The poet Louis-Honore Frechette devoted a poem to it in 1873. Charles Gill, the artist and poet, made the cape a centrepiece of his collection Le Cap Eternite. The white statue gleaming against dark rock became an icon of Quebecois identity, and the site remains a minor pilgrimage destination to this day.

Cap Trinite is the centrepiece of Saguenay Fjord National Park, drawing hikers, climbers, and cruise passengers to its base and its summit. The Statue Trail leads visitors on foot up through boreal forest to the ledge where Notre-Dame-du-Saguenay stands, offering a view straight down the fjord wall to the dark water below. From the river, excursion boats approach the cliff face closely enough for passengers to appreciate the full vertical scale, the statue appearing as a small white figure against the immensity of rock. Across the fjord, Cap Eternite provides a facing wall of comparable drama, the two capes framing Baie Eternite like stone gateposts. The fjord between them runs cold and deep, home to seals and belugas that sometimes surface in the shadow of the cliffs. In winter, ice forms along the shore and the cliff faces become encrusted with frozen waterfalls, turning the already dramatic landscape into something approaching the otherworldly.