Sun Temples also known as Henges were most commonly 660 feet in circumference that is achieved with a diameter of 210 feet. 660 and 666 were used in the numerological codex of Gematria to symbolize the sun.
History of Licking, County, Ohio 1881
The traveler between Newark and Granville will observe many of these mounds, a few yet pretty well preserved, even on the extensive and rich bottoms of the Raccoon ; but the better preserved works, and those probably the most interesting, are located upon the hills that shut in the valley. Captain M. M. Munson, who occupies a beautiful farm in the midst of these mounds, and who has made them something of a study, is confident that around the great alligator mound, located not far from his house, is a complete system of mounds and earthworks that point to it as a common center. However this may be, there is certainly a large circle of works in this vicinity, extending several miles in every direction, and seemingly connected with each other and with the "Old Fort" near Newark and its contiguous works. The Alligator mound is situated upon the summit of a hill nearly two hundred feet high, about six miles west of Newark; near Granville. The shape and form of this reptilian monster are distinctly presented, so that all admit, at the first; glance, that it was undoubtedly intended to represent the alligator or American crocodile. His enitire length is two hundred feet and ten feet. The greatest breadth of his body is twenty feet, and his length between the fore legs and hind legs is fifty feet.