The Location of Nihonbashi Bridge

This map shows the Edo city around 1630, A.D.
The orange part at the center shows the Edo castle. The yellow part around the castle shows the residence area for Samurai (warriors). It was about 68% of Edo city.
The green part near the sea shows the living area for commoners. It was about 16% of Edo city. The population of Samurai and commoners was almost the same. It was about 150,000 people each. So, about 300,000 people lived in Edo city. It means the population density of the commoners's living area was very high.
The light-blue part shows the area of the temples and the shrines.
The Nihonbashi Bridge was located at the center of commoners's area.