Get out on foot or bike and travel through the interior of Rodrigues. Roads are starting to be built to a good standard throughout the island. It's a small island so if you do get lost you should be able to follow one road and it will lead you to someplace that you should recognize or to somewhere where you can ask for directions. This is a good way to spend a day or evening.
During my visit I have not been much out there but I am sure that just wandering around would prove to be quite spectacular and out of the ordinary. However, while travelling to the capital, Port-Mathurin, I thought that "la Passe" was something amazing: the passage that fishermen take to leave the lagoon and that leads to the deep sea.