Urban Architecture From an Impossible Time
A typical example of the archeological ruins described above was found in waters 120 feet deep in the Gulf of Cabay, located off the western coast of India. It is estimated that the vast city, discovered by chance during an investigation on pollution, could date back some 9,000 years.
Using a sonar tracker, investigators managed to identify defined geometric structures at a depth of about 120 feet. From the site, they recovered construction material, pottery, sections of walls, basins, sculptures, bones, and human teeth. The carbon tests indicate that these pieces were 9,500 years old.
Before this finding, anthropologists thought that the area had not seen civilization before 2,500 B.C. This ancient city, therefore, was even older than the Harappan civilization, once believed to be the oldest of the subcontinent.
Another surprising case came in 1967, when the Aluminaut—an exploration submarine capable of submerging deeper than any craft of its day—casually discovered a “road” off the coastal zone of Florida, Georgia, and South Carolina. Found at a depth of nearly 3,000 feet, this road traced a straight line for more than 15 miles.
Even more surprising, this road had been paved with sophisticated cement composed of aluminum, silicon, calcium, iron, and magnesium. Despite its age, the road was found to be free of debris due to an underwater current that kept it clear.
This forgotten road still proved a worthy thoroughfare as the special wheels of the Aluminaut allowed the sub to actually travel along the enigmatic highway. Later, scientists exploring the area found a series of monolithic constructions at one end of the road. What technology could construct a long paved road that would remain in good condition for 10,000 years?
A more recent discovery of this type took place in 2004, when the same tsunami that battered the coasts of Southeast Asia also moved tons of sand from the cost of Tamil Nadu, India. The storm cleared years of dust that led to the discovery of the mythical city of Mahabalipuram.
According to local legend, the city of Mahabalipuram suffered a great flood, submerging it in a single day 1,000 years ago, when the gods became jealous of its beauty. The local inhabitants recounted that six temples were covered by water, but that part of the seventh remained on the coast. The team of 25 divers from the Archaeological Survey of India explored the extensive area covered with man-made structures, ranging at depths of between 15 and 25 feet below the water.
The scale of the submerged ruins covered several square miles, at distances of up to a mile from the coast. Conservative estimates of the age of these constructions range from 1,500 to 1,200 years old, though some investigators say they originate from up to 6,000 years ago.
http://weburbanist.com/2007/09/12/underwater-urban-archeology-7-submerged-wonders-of-the-world/
HiRes photos of the city
http://www.heralddeparis.com/got-ruins-undersea-archaeologists-release-new-photos/66899