The Blue Penny Museum at Caudan Waterfront is built around two stamps — the famous 1847 'Post Office' Mauritius issues that fetch millions at auction. The surrounding galleries trace the history of Mauritius from early Arab and Portuguese contact through the French and British colonial periods, with maps, paintings, and the stamps themselves displayed under low light.
The collection is small but high quality, and the curation is genuinely interesting if you give it time. Entry is around Rs 245. Open Monday to Saturday; closed Sundays.