Hiking Le Morne Brabant is possibly the best of all mountain excursions in Mauritius, as you get to see the famous undersea waterfalls at the end. It only takes 1.5 hours to go all the way up and while most of the trail is between easy to intermediate levels, part of it is quite steep and requires a guide.
This trip requires cost EUR 150 for up to 4 persons. It starts at 9am and ends at 4pm.