Complex sentence: The region of Abondance has been well known for its cheese since the 14th century thanks to production by monks from the "abbaye de Sainte Marie d’Abondance" monastery, which is near the Swiss border.
Split into simpler sentences: The region of Abondance has been well known for its cheese since the 14th century. This is due to cheese production in this area by monks from the "abbaye de Sainte Marie d’Abondance" monastery, which is near the Swiss border.