Prerendered Backgrounds?

Hello. I just want to know how to make one of those prerendered backgrounds like in final fantasy VII. If you could answer that would be appreciated.

if your game is going to be 2d or 2.5d then id say the best way is to get a plane and texture it. but if u want a background in a wide open 3d space than adding a skybox through Edit>Render settings would be best