circle Tokyo Lowlands (South) and the Kofuns

Tokyo Lowlands Map LEGENDS:
Dark red spot: Kofun
Dark green: Heights
Light Blue and Light Khaki: Swampy Flats
Darker Khaki: Bank
Blue: Waters

The map shows estimated coastline in the Kofun period (6-8c.). Archaeological sites mostly situate on the bank (slight heights such as natural levee, coastal dune or sand bank) which distribute here and there on the alluvial plain.
Lowland Kofuns are rare and not well researched so far. On the other hand, dense distribution of the Kofuns, not expressed in the map, are known on the terrace heights.