The site comprises two extremely steep-sided ravines in the south of the island, separated by a narrow, cultivated plateau and an uncultivated ridge. The riverbeds are affected by floods and landslides, and support a few habitations and cultivated areas, but the ramparts are unaltered. The site includes lowland and montane habitats (100–2,320 m), including mixed moist evergreen lowland forest, mixed montane forest, and montane shrubland, bushland and thicket. The most exposed, steep cliffs are bare rock.
See Box and Table 2 for key species. Rivière des Remparts supports the highest density of Puffinus lherminieri colonies known on La Réunion, and also a high density of Circus maillardi (10–15 pairs in 1997). All the other forest-living native birds of La Réunion occur, except Coracina newtoni. Historical accounts describe petrels Pterodroma sp. nesting in the upper part of the site; none have been found recently, but they may nevertheless occur.
Non-bird biodiversity: There is a wide diversity of native plant communities.
BirdLife International (2020) Important Bird Areas factsheet: Rivière des Remparts - Rivière Langevin. Downloaded from http://www.birdlife.org on 19/01/2020.