On the coast beyond the tiny village of Mahatsinjo, 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 the Route de l'Ouest just north of Hell-Ville, and easily reached by quad- or motorbike. The guide charges Ar7000.
Black lemurs play in the branches, making great photo opportunities.