Complex sentence: Included in the national park are historical industrial areas, including a former iron works area in Kirjakkala, which has many log houses from the 1800s which have been renovated to their original state.
Split into simpler sentences: Included in the national park are historical industrial areas, including a former iron works area in Kirjakkala. The iron works contain many log houses from the 1800s which have been renovated to their original state.