From the looks of it, it has some serious optimization issues. A large, mostly featureless or mostly static map is also a waste of time and resources. Build your ideal map in a separate file, then pare it down to only the useful portions and import it into your game project. Also, as some others have recommended, make sure that anything the camera doesn't see is removed from the render queue. There's no need to render something we can't see or animate anything that is too far from the player (something like an LoD mesh would be preferable, where a low-poly model with no animation or very simple animation is presented after X distance).