Mumbai here are some must visit spots of Maharashtra Mahabaleshwar Panchgani
If you want to check out cities-
Mumbai, Pune, Nagpur, Kolhapur, Satara, Nashik
If you want to experience nature-
If you want visit historical places-
there are so many forts from pune to kolhapur
Raigad is must.
Definitely Mumbai! Last time I was there I was with host from https://thecitizenseven.com and it was so helpful, because I didn’t have to think over all this issues. And it was so interesting, because I’m keen on photographing and he also was a photographer, so we visited all the top places for photos. Try it next time.