Two major river systems, the Arun and the Tamur, drain Nepal’s eastern ranges, upon which the monsoon unleashes its deluge with unparalleled vigour every summer.  Like the Karnali river in the west, the Arun predates the Himalaya, and rises north of Everest, in Tibet (where it is called the Phung Chu), passing between the major mountain massifs of Kanchenjunga and Makalu, at an altitude of under 1000m, meaning that the valley floor is a veritable sauna even in November.  From Makalu and the Arun valley to the tea estates of Ilam and the border with Sikkim, the lush, densely forested hills of eastern Nepal are mysterious, complex and thoroughly alluring. Deep, seemingly impenetrable valleys carve their way into the highlands from the south; primaeval, mist-swathed and alive with the chorus of birds and insects. In spring, mighty rhododendrons, magnolias and azaleas burst into flower, together with many varieties of orchid,... read more about Eastern Nepal