Very few visitors have heard about Îlet Bethléem, a magical spot by the Rivière des Marsouins that locals would like to keep for themselves. Reached after a 15-minute walk from the car park, it features an old chapel (1858) – still a pilgrimage site – and a smattering of picnic shelters amid lush vegetation. It's also an excellent swimming spot, with lots of natural rock pools. Follow the D53 in the direction of Takamaka, then turn left after about 1km (it's signposted).
Unfortunately, the area is sometimes sprinkled with rubbish.