What can you do in your free time?

Hey, I'm currently on vacation for a week because we had to take time off. Does anyone have any ideas about what I could do? Or how I could spend the time?
I can't think of anything and I don't really feel like playing or watching anything.
Ideally something that costs little to no money, since my training allowance went entirely towards the car (insurance for two months plus taxes), and I only have money left for petrol.
I've been bored for months and don't know what to do with my time, and now on vacation it's even worse.