https://www.unrealengine.com/marketplace/en-US/slug/countryside-windmills-barns
A peaceful scene with an extremely modular barn and a windmill which you can reuse. I've included prefabs as well as separate elements, such as boards, pillars, doorframes etc. Most of the models have a couple of interchangeable materials for better variation. Both daytime and nighttime demo levels are included.
Countryside Environment (Unreal Engine 4)