Southeast Asia Physical APHGOnline version Central and Southeast Asia map test. Southeast Asia physical features. Ap Human Geography. by White Raven 1 South China Sea 2 Gulf of Tonkin 3 Mekong Delta 4 Java Sea 5 Philippine Sea 6 Pacific Ocean 7 Annam Mountains 8 Mekong River 9 Irrawaddy River 10 Salween River 11 Irrawaddy Delta 12 Gulf of Thailand 13 Indian Ocean