Padanon here, these are my two cents.
The pianura padana sucks balls, there's no two ways about it. It's all an industrial/agricultural hellhole ridden with ticks and mosquitoes. However, it would be dumb to say northern Italy has no /out/, considering that we literally have the greatest mountain range in Europe from which the work "alpinism" literally comes from. You basically have a few options, all of them involving mountains because that's where nature is around here
>Alps
they speak for themselves. I'm only familiar with the dolomites since that's where I used to go with my family. If you care about hiking it's nothing less than fantastic, if you want to pitch a tent, make a fire and have a comfy larp then it's simply too crowded and regulated to do anything. With that being said, there's plenty of mountains and valleys (near Slovenia for example, probably also in other places but I'm not an expert) that are empty and nice. You just have to go out there and see for yourself, there are no shortcuts.
>Appennines
I know this range a bit better. Not as majestic as the Alps, but still gets around 2000m, which is still high. Many mountains aren't that steep and the lower altitude means there are more woods where you actually can wander off the trail and pitch a tent to have a wank (bearing in mind you ALWAYS have to be smart about it). The appennines in parma and reggio have very nice mountains from which you can see both the Alps and the mediterranean if the day is clear (look up marmagna, parco dei cento laghi, ventasso, cusna). Modena has nice mountains too. If you go more towards Romagna, the mountains are a bit lower but also wilder. In Forlì, for example, you have one of the largest natural preservations in Italy, which is foreste casentinesi
>Apuane
pic related, called Alpi Apuane but not alps, they are in the north of Tuscany . I got back yesterday from a 3 day trip with a tent and it was very comfy. I now have to cook lunch but I will post something