Down at the very bottom of Bangladesh, where the Ganges, Brahmaputra and Meghna rivers break into countless channels before meeting the Bay of Bengal, lies the largest mangrove forest on Earth. The Sundarbans South Sanctuary is one of three protected wildlife sanctuaries in the Bangladeshi part of the forest, and the whole area is a World Heritage Site. This is a world of water and tide: creeks, rivers and islands thick with sundari trees, from which the forest may take its name, along with gewa, keora and golpata palms, all standing on breathing roots that poke up through the mud.
It is also one of the last strongholds of the Bengal tiger, which has adapted to swimming between islands and living on fish, crabs and deer. Spotted deer, wild boar, monkeys, saltwater crocodiles, river dolphins and an extraordinary range of birds, including kingfishers of several kinds, share the forest. People live with the tigers here too: honey collectors, woodcutters and fishermen work the edges and the creeks, and their prayers to Bonbibi, the forest goddess, show how seriously the danger is taken. Cyclones regularly sweep in from the Bay, and the mangroves act as a vital shield for the land behind.
Let us be honest about the riding: there is none. The forest has no roads, and the sanctuaries can only be visited by boat with a permit and an organised guide, usually from Mongla or Khulna, and trips often last two or three days. The ride part of the journey ends on the mainland, on flat, crowded roads through rice paddies, shrimp ponds and villages, where you share the tarmac with cycle rickshaws, buses and trucks. The light over the water at dawn and dusk is unforgettable, but the humidity and monsoon rains from June to September make the cool, dry winter months the time to go.
Khulna, the regional city, has fuel, hotels and supplies, and Mongla, the port town on the Pasur river, is the usual departure point for boats. Expect simple food on board: rice, lentils, fish curries and plenty of sweet tea. Bring insect repellent, sun protection and patience, and respect your guides' instructions about where and when to step ashore.