A number of historic buildings have blue information boards in Malagasy, French and English, such as the house belonging to Cassam Chenaï, an Indian trader who settled in Diego around 1895. It's a pleasant walk along Rue Colbert towards the sea and then along Rue Richelieu to discover more, such as the imposing Hôtel des Mines, the Japanese Monument, La Résidence and the Tribunal.
The Jardin Tropical is a delightful 10,000-sq-metre garden in a quiet residential area. Children will enjoy exploring the three growing areas of primary forest, a rock garden and full sun to search for crocodiles, chameleons and porcupines.
If you're planning to visit the Black Lemur Camp south of Diego Suarez or the Loky Manambato Protected Area in Daraina near Vohémar, the Fanamby NGO has an office in Diego Suarez for information and bookings.