Assam tea is produced here along with petroleum and Assam silk. The state has conserved the one-horned Indian rhinoceros from near extinction, along with the pygmy hog, tiger and various species of birds. It provides one of the last wild habitats for the Asian elephant. The economy is aided by wildlife tourism while the Kaziranga and the Manas National Parks are designated as World Heritage Sites. Sal tree forests are found in the state, which as a result of rainfall looks green all year round.