Billed as a botanical hiking trail, Macolline is an arboretum on the banks of the River Ankavanana, 3km north of Antalaha. Guided walks of three to six hours can include lunch and a pirogue ride. There are fruit trees and medicinal plants, as well as frogs, chameleons, millipedes and butterflies. For Ar5500 you can plant a tree and make a contribution to the organisation. Proceeds go towards local villages and support former leprosy sufferers through the organisation Comité d'Aide aux Lépreux d'Antalaha (CALA).