**Updated 8-14-2012
A series of circular features has been documented that range in size from 90-35 feet in diameter. The sites in Saudi Arabia are ancient stone constructions, but the other circular sites in this article remain a mystery.
Underwater Circular Features off the Coast of Greece with similar dimensions and rectilinear features nearby.
Aligned mounds have been found just 12 miles West of the city of Abu Sidhum in Upper Egypt along the river Nile.
A series of linear features have been documented along the shorelines and inlets of the United Kingdom. Many of the features appear similar to ancient fish traps dated to be 1,000 years old.
Two underwater linear features off the coast of the Bahamas.
Underwater, linear feature found in Cornwall, England.
Underwater mound features seen off the coast of California.
A large, gridded topographic anomaly in the Atlantic Ocean seen with Google Earth.
This rectilinear feature has been spotted off the coast of NC, 22 miles SE of Harkers Island, North Carolina.