The two national parks near Saint-Louis are genuine highlights, and neither requires more than a day. Djoudj National Park, about 60km north on the Senegal River delta, is one of the most important bird sanctuaries in the world — three million migratory birds winter here between November and April, including spectacular concentrations of pelicans and flamingos. The reserve is a UNESCO World Heritage Site in its own right.
The Langue de Barbarie National Park lies 20km south of the city, a thin strip of sand and brackish lagoon where sea turtles come to nest. Boat trips through the park's waterways are a good way to see the birdlife without the crowds of Djoudj.
For a slower journey, boat trips east along the Senegal River to the old colonial towns of Podor, Bakel, and Matam take you deep into the Sahel and its distinctive mud-brick architecture — though these require more than a day and need advance planning.