Southeast Asia, South-East Asia, South East Asia or Southeastern Asia is a subregion of Asia, consisting of the countries that are geographically south of China, east of India, west of New Guinea and north of Australia. The region lies on the intersection of geological plates, with heavy seismic and volcanic activity. Southeast Asia consists of two geographic regions: Mainland Southeast Asia, also known as Indochina, comprises Cambodia, Laos, Burma (Myanmar), Thailand, Vietnam and Peninsular Malaysia, and Maritime Southeast Asia, which is analogous to the Malay Archipelago, comprises Brunei, East Malaysia, East Timor, Indonesia, Philippines, Christmas Island, and .