Kaziranga National Park is an Indian national park and a World Heritage Site in Golaghat and Nagaon districts of Assam, India. It is refuge for the world's largest population of great one-horned rhinoceros. Kaziranga has the highest density of tigers among protected areas in the world and was declared a Tiger Reserve in 2013. The park has large breeding populations of elephant, wild Asiatic water buffalo and swamp deer. Kaziranga is recognized as an Important Bird Area by Birdlife International for conservation of avifaunal species. The park has achieved notable progress in wildlife conservation with respect to other protected areas in India. Kaziranga was declared a Tiger Reserve in 2013. Kaziranga is a vast stretch of tall elephant grass, marshland and dense tropical moist broadleaf forests crisscrossed by four main rivers — Brahmaputra, Diphlu, Mora Diphlu and Mora Dhansiri and has numerous small water bodies. Kaziranga has been the theme of several books, documentaries and songs. The park celebrated its centenary in 2014 after its establishment in 1905 as a reserve forest. Local legend tells about a village girl named Ranga and a young man named Kazi from Karbi Anglong who fell in love. Their parents would not give consent to the affair, so the couple continued to meet each other in the forest. One day, they went into the forest and never returned. Since that day, the people call the forest Kaziranga.