That would depend on the preference of the person to choose just one structure. There are many structures that are well-known in Tokyo such as the Tokyo Big Sight, which is the nickname for their international exhibition center, as well as the Tokyo Dome, which was a Baseball stadium that became open to the public in 1988.
Tokyo is a major city. I think it is near mountains, but if you have it, go on Google earth and enable geographic features after searching Tokyo
soffit, an architectural feature
Soffit
The major architectural feature of the Colosseum and other Roman buildings was the use of concrete.
No. Tokyo is the capital city of Japan. Tokyo is located on one of Japan's main islands called Honshu.
A battlement.
The columns
Barrell vaults
The columns
Those letters spell gargoyles, an architectural feature.
a ballcourt
A breezeway is a type of architectural feature that allows a breeze to cross through the hallway. This may be for aesthetic purposes or for functional purposes by creating a cooling breeze for travelers crossing the breezeway.