I want to launch a school forum for a country. I'm in dilemma as to how to design this forum.

Country will have many states, each state will have cities, each city will have many schools. Each school will have many classes( 1st - 12th).

It looks like this:

States -> Cities -> Schools -> Classes

I want to make each class as forum.

Now the biggest problems are two fold:

1. If I were to list even 1000 schools it will create huge number of forums and I don't think forum softwares(PHPBB, MyBB) are designed to support these many
2. Secondly creating and maintaining huge forums is also very difficult. Ideally I'd like to duplicate existing forum hierarchy to new one.

I've done lot of search and I've found that such type of forums are infeasible and such designs don't work. Leave alone the fact the nobody uses such a forum.

Keeping in mind this, how should I go about designing this forum?