Grenoble is approximately 1h15 from Annecy, you can take a cable car up to the Bastille Fort and enjoy a lovely view on the city and the Alps mountains.
When I was there, we took the cable car up then walk down the stairs which was fun, easy and you can take your time to look at the view.
Grenoble is a big city where you can do some good shopping and find a variety of restaurants but in the summer it can be pretty hot there with no air.
The Bastille and Cable car is my favourite thing to do in Grenoble.
Enjoy the local specialities (les noix, la Chartreuse, le Bleu du Vercors, le Saint Marcellin, les ravioles du Royans)
Annecy is about an hour drive to Grenoble, public transport to get there is quite good, train or bus, but if you wish to book a taxi, do not hesitate to contact me https://www.taxi-massingy.com/
First-class museums, full of history castle, and unique places that reflect the city’s desire to always surprise and innovate; Grenoble has been successfully reinventing itself for more than two centuries, often leading the way for cultural, social, and industrial trends. It seems almost impossible to sum up Grenoble in a few essentials. At least the mountains are an ever-present constant, waiting at the trend of every corner. You will first learn to name them before curiously exploring them, and standing breathless in front of their beauty.