Eastern Bhutan is a densely populated region and remains the kingdom's hinterland. The dominant language here is Sharchop. The Manas river system, Bhutan's largest river and a major tributary of the Bhramaputra's, drains most of the eastern Bhutan. It is at much lower altitude than Central and Western Bhutan. The warmer climate is suitable for growing corn, rice, wheat, potatoes and surprisingly lemon grass. It is known for its stunning hand-loomed textiles and the weavers are all masters of the supplementary weft-weave technique. Eastern Bhutan is the least travelled area of the country and is where many of the kingdom's most ancient spiritual sights are found.