The bloodlines of East Kalimantan flow through its rivers and waterways, which support countless floating villages, some of which are centuries old. A major chunk of tourists to the Kalimantan island will inevitably wind up in East Kalimantan, usually to enjoy a river cruise on Indonesia’s second largest river, Sungai Mahakam, or to get a taste of the culture of the Apo kayan people.East Kalimantan is actually largely a hub for the Indonesian oil and gas industry. However, East Kalimantan's hinterlands are definitely fascinating and the forest cover is immense, where it's easy to spot orangutans and other primates. There's also some spectacular diving off the east coast – especially off the Derawan island, which is also famous for a freshwater lake infested with jellyfish!Things to do in East Kalimantan: River cruising up the Mahakam for a peek into the contemporary Dayak culture. Don't expect too many traditional longhouses (or headhunters). Also diving and beaching on Derawan island in the Celebes Sea.Get in: Balikapan and Tarakan are the gateways to East Kalimantan, with air connectivity to other Indonesian cities. Tarakan is also connected to Malaysian Borneo via ferry to/from Tawau.