there is great nature in Serbia. We have some beautiful mountains, and big part of them is still not that crowded and commercialized.
i was a sea person, not sure am i still :D now i think i am half half :D
i think you can if you don't get caught :D it is used by a local kayak club, not sure for what exactly. so if you get to it you would probably not be in great trouble if you stay a night there :D
I thought it is private property :) However, i believe they could rent it out for good money. I think there are plenty of people willing to pay big money for something like that but of course, it depends in what condition the cabin is in and if it has some permits from the authorities. Still, I thinks it's cool :)
Serbia is on my wish list :))