Boating on the Rio Preguiças is one of the Lençois' main excursions. Along the way, you can admire the natural beauty of the area, all too often in danger. It's also a human adventure. You'll meet the communities who live along the various rivers that run all the way to the Atlantic coast. By fast motorboat (no pollution-free boats yet, alas), groups travel up the Rio Preguiças along the Pequenos Lençois Maranhenses to the Atlantic coast.

The riverbanks reveal their rich biodiversity: mangroves, aguapés (water plants), buritis (palms), açaizeiros (endemic trees of the Nordeste), coconut palms, and herons and kingfishers. The closer you get to the coast, the more the dunes come into view.

Stop at Vassouras. Behind the few riverside huts and the small Tenda dos Macacos restaurant, you can climb over small dunes and see a small lagoon. Do not feed the monkeys.

Stop off at Mandacaru, where you can climb the 178 steps of the pretty black-and-white Preguiças lighthouse overlooking the village for a breathtaking view of the park. Opposite you can see the ocean and Caburé beach.

Caburé. The boat finally arrives at the tiny village of Caburé. A freshwater river borders the village, and just beyond the sand dune lies the sea and its miles of deserted beaches. On Caburé beach, a few small pousadas have opened their doors to allow some to extend this experience.

Is the risk of overtourism contained?