While Peninsular Malaysia is geographically situated in Mainland Southeast Asia, it shares many similar cultural and ecological affinities with surrounding islands, thus it is often grouped with them as part of Maritime Southeast Asia. Geographically, the Andaman and Nicobar Islands of India is also considered a part of Maritime Southeast Asia. Eastern Bangladesh and Northeast India have strong cultural ties with Mainland Southeast Asia and are sometimes considered transregional areas between South Asia and Southeast Asia. To the east, Hong Kong is sometimes regarded as part of Southeast Asia. Similarly, Christmas Island and the Cocos (Keeling) Islands have strong cultural ties with Maritime Southeast Asia and are sometimes considered transregional areas between Southeast Asia and Australia/Oceania. On some occasions, Sri Lanka has been considered a part of Southeast Asia because of its cultural and religious ties to Mainland Southeast Asia. The eastern half of the island of New Guinea, which is not a part of Indonesia, namely, Papua New Guinea, is sometimes included as a part of Maritime Southeast Asia, and so are Guam, the Northern Mariana Islands, and Palau, which were all parts of the Spanish East Indies with strong cultural and linguistic ties to the region, specifically, the Philippines.
