The Sundarbans is the largest mangrove forest on Earth, spanning the delta where the Ganges, Brahmaputra, and Meghna rivers meet the Bay of Bengal. A UNESCO World Heritage Site, it's the last remaining natural habitat of the Royal Bengal Tiger, alongside spotted deer, saltwater crocodiles, and over 300 bird species. Most visits are by boat, drifting through narrow tidal channels and dense mangrove canopy that few other places in the world can match. Trips typically depart from Khulna or Mongla, with multi-day boat cruises the most popular way to experience it.