You have been sentenced to life in a micronation of your choosing (Sealand, Molossia, etc.) The micronation must have actual land and you may never leave that land. What micronation do you choose?
Edit: clarification of the rules. A micronation is by definition not recognized internationally. As a result, small sovereign states like the Vatican are not allowed.
Also you can’t just make your own micronation wherever you want. It has to already exist.
The closest to me AFAIK is Sealand, but I’d rather not, tbh. I do actually have a passport from Waveland, declared as part of a Greenpeace campaign some years back and based on Rockall, but also not too appealing as a long-term residence.
At one site that I lived and worked on for several years, we discussed declaring unilateral independence on several occasions. It was a shingle spit nature reserve and seemed a promising location, but we never did. Well, not so far.
Overall, the Free Borough of Llanrwst looks a good bet. I have been there and definitely enjoy the area.