Odaiba is a landfill in Tokyo Bay. This area is called the Tokyo Rinkai Fukutoshin area. Maybe you can understand as a whole by taking a water bus.
There are many gulls on the coast, many parks and wild birds are often seen, so walking on a sunny day is very comfortable.
In the seaside park, you can find sea basses, blackcurrants, and other interesting things; there is even a small replica of the Statue of Liberty along the shoreline.
As for Odaiba, there are other landmarks such as Rainbow Bridge, Fuji TV with its insignia spheres, Aqua City, Palette Town and the like.