Isalo National Park, National park in Ihorombe, Madagascar

Isalo National Park protects a Jurassic sandstone massif that runs nearly 100 km north to south, eroded into canyons up to 200 m deep, flat-topped mountains and steep-sided outcrops called runiforme. The park covers about 81,540 hectares between the Malio and Menamaty rivers, with elevations from 510 to 1,268 m. Its pale yellow, tan and grey rock walls rise above dry golden-brown grass.

The park was established as a national park in 1962 and came under the authority of Madagascar National Parks in 1997. This transition formalized protection of the area for future generations.

The Bara, traditionally nomadic cattle herders, live around the massif and keep zebu; the park holds their burial sites as well as older Sakalava graves. The name Isalo is also given to the eroded sandstone massif itself, whose odd "runiforme" shapes take their term from the French for "carved".

Visitors need to arrange guided tours through Ranohira town, as independent exploration is not permitted. Trails range from short daytime walks to multi-day treks depending on fitness and interest.

The park is home to 77 bird species, including Madagascar's Benson's rock thrush, along with 14 lemur species and plants that have adapted specifically to sandstone environments. This variety reflects how the isolated plateau creates its own ecosystem.