The dominant geographical features of northern India are the Indo-Gangetic Plain, known for its fertile soil and perennial rivers, and the Himalayas which cut the region off from the rest of Asia. North India has been the historical center of the Maurya, Gupta, Mughal and British Indian Empires. Hindi has the largest number of speakers in the region. North Indian original vegetation is predominantly deciduous forest because of its tropical location. For the Tourists, there are plenty to see, experience and learn in this part of the world. The important National Parks and world heritage sites of this region include the National Parks at Corbett, Kanha, Kaziranga, Sundarbans and Nanda Devi, Bharatpur Bird Sanctuary and the one and only Valley of flowers in the Himalayas. The origin of sacred river Ganga, Yamuna and sources of many other important rivers are in northern India. Pushkar Mela, perhaps the largest cattle fair in the world, attracts tourists from all over. The highlight of this region certainly centers around the historical monuments of Taj Mahal at Agra, Hawa Mahal at Jaipur, Lake Palace at Udaipur and the Red Fort and Qutub Minar at Delhi and many more. Surreal landscapes of the Ladakh region, often termed as "moonscape, Natural beauty of the North East and the Deserts of Rajasthan add to the variety of this enchanting region of India.