Legend of Mudalu: Civilization Under Water
Undersea Wall Discovered off the Coast of Taiwan
According to a Taipei Times article, in July 2002, members of the Taiwanese Underwater Archeological Institute discovered a wall 100 meters long and 28 meters deep off the coast of Penghu. They had been searching for a legendary underwater town and possibly a temple, and they discovered this wall which has been dated between 7000 and 20000 years. Penghu is an island off the west coast of Taiwan.
A research fellow with the National Museum of History's Marine Archeology Team expressed the hope that they "might even be able to prove that some truth lies behind the legend of Mudalu."
The Ketagalan were supposed to be an advanced megalith-building culture with a written language.
Sonar soundings apparently indicate similar structures. The article mentions another discovery 20 years ago off the coast of Okinawa, as well as a cross-like structure found in 1982 in waters near Penghu's Hujing Island. In addition, other underwater wall-like structures have been found since then. (1)
References
[1] http://www.taipeitimes.com/News/feat/archives/2002/12/01/185543
Taipei Times, Sunday, Dec 01, 2002, New submarine discoveries spark interest in submerged cities, By Gavin Phipps