The Grand Morin is a river located in the Île-de-France region of France. It is a tributary of the Marne River and flows through several communes, including Château-Thierry and La Ferté-sous-Jouarre. The river is approximately 70 kilometers long and plays a role in the local ecosystem and agriculture. The Grand Morin is known for its scenic beauty and recreational opportunities. It is popular for activities such as fishing, kayaking, and hiking along its banks. The river also contributes to the region's biodiversity, supporting various plant and animal species in its surrounding habitats.