In the Ice Age, Australia, Papua and Seram Island was a large landmass called "The Sahul Continent" but together with Sulawesi, Lesser Sunda Islands, Maluku, Luzon and Mindanau were separated from the mainland Asia by the Walace Line. The Sundaland, consisting of Java, Sumatera, Kalimantan (Borneo) and Malay Peninsula, was also a large landmass attached to the mainland Asia.
My theory is that Atlantis is in Java Sea, a part of the Sundaland that was drawned by the melting of the ice, especially during the Younger Dryas stadial about 12,000 years ago. Java Sea is located north of Java Island. I found a lot of proofs in this location.
See this figure for the explanation.
Post Edited (23-Apr-15 18:02)