[jcranmer]

The tricky thing is that any text content has to have translation. You might be able to get away with not translating maps, since place names tend to be more stable (or at least generally pretty easy to work out) across different languages. For example, "Pologne-Lituanie" is going to be within the capability of most English speakers to work out, even if they've never heard of "Poland-Lithuania".

It is possible to link images and other things via Wikimedia, and my understanding is that Wikipedia does push for people to do this.