The Thrumshingla Pass at 3,780 meters is the second highest motor-able pass connecting the central and eastern regions of Bhutan and is a must stop over for amazing views, landscape and the beautiful Rhododendrons. The In-situ Rhododendron Garden located at the Pass offers a short 45 minutes walk to see the 22 different species of Rhododendron with the best time to visit being from March to May. 

The Pass is located inside the Phrumsengla National Park and an excursion of the Pass is the best option to visit a National Park since there are no animal safaris per se in Bhutan. The Park is one of the largest parks in Bhutan stretching over an area of 905 Sq.km spread through the four eastern valleys of Bumthang, Monggar, Lhuntse and Zhemgang. The elevation ranges from 800 meters above the sea level to more than 4,500 meters with vegetation ranging from subtropical broadleaf in the south to alpine grasslands in the north.

The Park is home to a wide range of flora and fauna including many endangered species due to the combination of different vegetation zones, varying temperatures from -210 C to 130 C in the northern region to as low as 80 C in the south. The Park has a record of 361 bird species including globally endangered Rufous-necked Hornbill, blabbers, hornbills, nuthatches, crimson pheasants, Partridges and Tragons and many more. The Phrumsengla National Park is one of the best bird watching destinations in Asia and a haven for ornithologist and bird watchers. Exotic mammals like the Royal Bengal Tigers, Red Panda, Himalayan Black Bear, Common Leopard, Clouded Leopard, Musk Deer and Golden Cat are commonly sighted even as you drive along the highway.