São Tomé is the largest of the islands, approximately 836 km2, and lies southwest of Príncipe.

The Tinhosas islands are two unvegetated rocky islets lying 22 km south of Príncipe.

The upper montane forests and cloud forests include plants characteristic of afromontane flora, including Olea capensis, Syzygium guineense, and Pauridiantha floribunda, and the endemic trees Afrocarpus mannii, Tabernaemontana stenosiphon, Homalium henriquesii, Croton stelluliferus, Polyscias quintasii, and Craterispermum montanum.

The endemic subspecies of olive ibis on Príncipe, B. o. rothschildi, is probably the rarest bird in the archipelago.

[1] Protected areas in the ecoregion include Obo Natural Park, which includes the Tinhosas islands and portions of São Tomé and Príncipe islands, and the Annobón Natural Reserve on Annobón.