The Sinnamary River rises in the interior highlands of French Guiana and runs roughly 260 km to the Atlantic coast, where it meets the sea at the town of Sinnamary. The lower river, between the town and the coast, is wide, brown, and lined with mangroves — good for birdwatching from a pirogue. Herons, kingfishers, and the occasional caiman are reliably present.
Upstream, beyond the town, the river narrows and the jungle closes in. Pirogue trips to the various saut (rapids) along the upper river are the main tourist activity in Sinnamary. The trips range from a few hours (Saut Caouanne or Grégoire Creek) to multi-day expeditions reaching Saut Lucifer deep in the interior. Local boatmen at the riverside can arrange trips; prices and timing should be agreed in advance. The trips involve some portaging around the rapids and require a reasonable level of physical fitness.