There are many high plateaus, rift valleys, interior basins and ranges, and also more volcanoes in the southern half of the island (west coast) than in the northern half. The highest peak is Mt. Kerinci (3800 m). The Batanghari, the longest river in Sumatra, starts at Mt. Kerinci and runs through the Jambi Plains and the town of Jambi itself. A belt of coastal marshes runs down the whole southeastern coast. The 'Green Deserts' of South Sumatra are up to 250 km wide, some of the largest swamps in the world and as extensive as the infamous Sudanese Sudd. Some of Indonesia's biggest oilfields are located in South Sumatra around Palembang Province. This is also elephant country. When crossing a river in this region, be sure to address a crocodile as 'grandmother' and call a tiger 'grandfather'. Tigers' claws are a powerful good luck charm and their whiskers grated in alcohol will make a man as strong as 10 men. Antarruang Tours and Travel, JI. Tanah Abang Due 53, Jakarta Pusat, offers 15-day tiger-hunting safaris in South Sumatra (staff included) at rates from only Rp2-6,000,000 plus 5% commission for a minimum of 6 persons.