On the coast beyond tiny Mahatsinjo village, there's an enormous sacred banyan tree planted by the Queen of the Sakalava tribe in 1836. Nowadays, the Queen of Nosy Be makes an annual pilgrimage to sacrifice a zebu and gain benediction. Shoes must be removed before approaching the tree, and if you have bare legs, a wrap will be provided.
The tree is signposted from Rte de l'Ouest just north of Hell-Ville, and is easily reached by quad- or motorbike.
Black lemurs play in the branches, making great photo opportunities.