Route Parameter, Custom Model Binder or Action Filter?

This definitely sounds like a job for an action filter. You can do DI with action filters not a problem.

A custom model binder for your Site type sounds like a good idea to me. You will probably also want an action filter as well to catch "null" and return not found.

I cant really gove you an answer,but what I can give you is a way to a solution, that is you have to find the anglde that you relate to or peaks your interest. A good paper is one that people get drawn into because it reaches them ln some way.As for me WW11 to me, I think of the holocaust and the effect it had on the survivors, their families and those who stood by and did nothing until it was too late.