Brahmaputra
Its remote course, which travels through many protected areas and national parks, allows for some unique wildlife spotting opportunities as elephants, tigers and even Indian rhinoceroses are known to make their home here.
While the river, the fastest-flowing of its kind in the world, has its origins in Tibet and runs through India, China and Bangladesh, on Great Rail Journeys' Assam & the Mighty Brahmaputra tour, we join the waterway as it cuts a path through the fertile Assam plains, an area famed for its tea production. Cruising through a section of the Brahmaputra with a rich biodiversity, it's possible to spot turtles and otters frolicking in the shallows just a short distance from the charming and colourful Chang Chars - stilted houses that help protect locals from fluctuating water levels.