This site contains information about remains of Joumon era (Joumon era is roughly B.C. 10000 - B.C. 300) in Gunma prefecture, which is located about 100 to 200 km northwest of Tokyo.
This site is written in Japanese, and no versions in other languages are available now.

If somebody needs the English version,please let the author (Eiji Wakimoto) know it by e-mail (JBB01432@nifty.ne.jp).
Although I cannot promise anything, I think I will try to make the English version if requested by many persons.

See also ...
About the romanization method of Japanese words in this web site