There are a lot of activities that you can partake in once you arrive. You can explore the old streets of San Giulio, hike the lake's hills, taste the local cuisine, and spend your vacation money on souvenirs and other bits and bobs. One of the best things to do on Lake Orta is, of course, swim in it. As long as you remember to be respectful and obey the rules, you should be in for a treat!