The Arboretum d'Antsokay is the best introduction to the strange plant life of southwest Madagascar. Just outside Toliara, it protects and labels species from the spiny forest: pachypodiums, euphorbias, didiereas, baobabs, and other forms that seem designed by drought.
Take a guided walk if possible. Without explanation the landscape can look simply dry; with a guide, it becomes one of Madagascar's most distinctive ecosystems and a good reason to slow down before rushing to the beach.