The Bouche du Roy is where the Mono River flows into the Atlantic at the Benin-Togo border — a wide, layered estuary of lagoons, mangroves, sandbanks, and fishing villages that forms part of a UNESCO Biosphere Reserve. You get here by pirogue from Grand-Popo, a journey of 30 to 45 minutes depending on the tide and the current.
The birdwatching is genuinely excellent: herons, egrets, pelicans, and waders work the shallows, and the mangroves shelter species that are hard to find elsewhere on this coast. The fishing villages built on stilts over the water are inhabited by communities whose economy has centred on this estuary for generations. Local guides can arrange visits and explain the significance of the wetland system, which also forms an important buffer against the coastal erosion that has eaten into Grand-Popo itself over recent decades.