Edo is very similar to Venice in many ways, since the main method of transporting goods in both cities is by canal. Much of downtown Edo (not including the Shogun's castle) was built on land reclaimed from the bay. The rivers and canals form the broadest "roads" through the city.
The early Shoguns also built an extensive network of canals in the countryside outside Edo. Several large rivers flow through the Kanto region, and these rivers have been linked by canals that allow goods to be transported by ship to and from all the large towns in the region. The sea and rivers are almost as important to Edo as the land. This may even be how "Edo" got its name, which can be translated "The Door to the Bay"