Map of remains in Munakata-city

I made a web-map of remains, such as tumuli, in Munakata city with the Google Mymap.
The remains were classified and colored by period:

• Orange: The Jomon period (- the 10th century B.C.)
• Yellow: The Yayoi period (the 10th century B.C. - the early 3rd century A.D.)
• Green: The Kofun period (the 3rd century - the 7th century)
• Deep Brown: After the Heian period (after the 8th century)
• Gray: The era is unknown.

This map shows that the ancient Munakata tribe was energetic in the ancient times, who had faith in the Oki-no-shima that becomes the world heritage.
It also shows that the activity of the tribe has changed with the times. The living range of the people expanded from the coastline into the bay-side (low lying grounds were once inner sea), and then they began to exploit hillsides.
These changes should have reflected in the development of the Oki-no-sima faith.

I hope if you would enjoy this map.
Thank you.