The Copolia Trail on Mahé Island is one of the best hikes for it's effort to reward ratio. It's a moderate hike (relatively easy), and is around a 1.8 km return. It's Located in the Morne Seychellois National Park, you can reach the trail by car or bus. It costs 100 SCR (£5 / $6) for non-residents over 12 years old and is open from 8 am to 4 pm.
The path is well-maintained and leads to a breathtaking mountain top viewpoint, with views over the surrounding islands and ocean.