Tinsukia Tea Oil Palm Digboi Arunachal Border Assam

Tinsukia district in the upper Assam Brahmaputra valley contains the oldest oil well in Asia — Digboi (1889), where Assam Oil Company first struck oil and built Asia's oldest surviving refinery — a heritage industrial site that continues to produce crude oil from the same Nahorpung field. The district's tea gardens in Margherita, Doom Dooma, and Tinsukia town have some of the largest and oldest estates established by British planters in the 1840s-50s. Tinsukia borders Arunachal Pradesh and the Dibru-Saikhowa National Park on the Lohit river — one of the last habitats of the feral horse (Moh-Mara horse), Gangetic river dolphin, and hoolock gibbon in the Brahmaputra floodplain islands.