This 43,200-hectare park makes a good day trip if you're in the area. While it may not be a generalist’s first stop, it's certainly worth a detour as you follow the remote coastline south. The park's large and ancient salt lake hosts some part-time resident flamingos (April to October) and the lake doubles in size during the rainy season; it's considered an important wetland. There's a sacred cave pool, the grotte mitoho, with some endemic blind catfish.
Locals believe the cave is home to the Antambahoka, an invisible people, and animal sacrifices still occur here from time to time. Amid the rampant spiny forest, watch also for a large banyan tree full of parrots and ring-tailed lemurs and whose tendrils fall several storeys into a flooded sinkhole. The park is home to four further lemur species, although most are more easily seen elsewhere. Verreaux's sifaka are commonly seen during daylight hours, and keep an eye out for sleeping nocturnal species such as the tiny grey-brown mouse lemur, fat-tailed dwarf lemur and white-footed sportive lemur.
The MNP office is located in the town of Efoetse, 3km from Ambola. You can arrange a mandatory guide and itinerary here, and a map of all the current routes is on display. There are several circuits, from 30 minutes to 3½ hours in length. A good English-speaking guide is Laurent.