Visit Jaldapara National Park or Gorumara National Park both situated in the terai of the Himalayan foothills. Both are famous for their Rhino and Elephant populations, not to mention the wide ranging flora and fauna available.  Stay overnight in the forest guesthouses and wake up early morning to take an elephant ride where you will get the chance to see such wildlife as the one horned rhino, barking deers, bisons and maybe even a spotting of the Royal Bengal Tigers.