We joined a boat excursion for the day from Rio, and after a boisterous ride out to the island with singing musicians and dancing Brazilians, we spent the day swimming, sunbathing and diving off the boat.
A day excursion was fantastic, but spending a few days (as many of the backpackers we met were doing) would be even better.
Formerly a prison (very effective location… why would anyone want to escape?), the Big Island has snorkelling, hiking trails, surfing and scuba diving. There is a handful of restaurants and accommodation in the main town of Vila do Abraão, where most of the ferries from the mainland dock.
Good to know: There are no ATMs on the island.
If you are ever in Rio, ensure you make time for trip to Ilha Grande.