Parc National Andringitra is the pièce de résistance of the wider Massif de l'Andringitra. It encompasses a high-altitude granite plateaux of epic beauty, small tracts of primary rainforest, scenic trails along mountain streams and waterfalls, and Pic Boby, the highest accessible mountain in Madagascar.
The best season to visit the national park is from June to November, when the rains aren't relentless (between January and March heavy rains make access to the park very difficult). Afternoon mists are common in these high altitudes and you should be prepared for bad weather at any time of year. If you are climbing Pic Boby, you will need a flashlight with several hours of battery life as the summit attempt generally starts way before dawn so that you can be there for sunrise.