On your last day, take a trip to Lake Paladru, located about an hour's drive from Grenoble. This picturesque lake offers a variety of outdoor activities, such as swimming, kayaking, and paddleboarding. Relax on the sandy beaches or explore the surrounding nature trails. In the afternoon, visit the Château de Virieu, a medieval castle overlooking the lake. Enjoy the peaceful atmosphere before returning to Grenoble in the evening.