Southeast Asia is a region of Eurasia that spans 4,545,792 square kilometers and consists of eleven different countries. Being spread between the mainland and various islands, Southeast Asia is a geographically diverse region with jungles, volcanoes, and even mountain ranges. Many languages are spoken throughout the region and a wide variety of cultures are practiced by various ethnic groups. Southeast Asia is the third most populous region in the world which has led to the development of such a wide range of ethnic groups. Major religions in the region include Hinduism, Buddhism, and Islam. The French managed to colonize the mainland region of Southeast Asia and called it French Indochina. This lasted until the colonial period ended and then the region was renamed Southeast Asia.