Air level of the map.

I think it’s best for heroes to end up there naturally, i.e., after death. A hero is killed in battle – and he ends up in heaven, where the Valkyries take him (instead of him returning to the tavern). Living heroes have nothing to do there, except perhaps to communicate with the spirit of the deceased through some kind of magical window. And let dead heroes populate heaven and fight with other dead heroes from the enemy.