Sainte-Marie is the Catholic cathedral of Libreville, set just back from the waterfront in the older heart of the city. The building dates from the late nineteenth century and was extended in the 1950s; it is the seat of the Archdiocese of Libreville, which covers the whole country.
The interior is whitewashed and cool, with a long nave and a small set of stained-glass windows behind the altar. It is open daylight hours; visit outside Mass and you can usually look around quietly.