If you want to see a flip side to surf-and-sand Bahia, or have time for only one excursion into the Northeastern interior, this is it. Lençóis is the prettiest of the old diamond-mining towns in the Chapada Diamantina, a mountainous wooded oasis in the dusty sertão (backlands of the Northeast). While the town itself has charming cobbled streets, brightly painted 19th-century buildings, and appealing outdoor cafes and restaurants, the surrounding areas are the real attractions. Caves, waterfalls, idyllic rivers and panoramic plateaus set the stage for some fantastic adventures, with the town of Lençóis serving as a base for treks into the Parque Nacional da Chapada Diamantina and for sights outside the park.