Map the interior surface of a cylindrical space station.

[Thurlor]

I was thinking that it need not be sci-fi in nature. Even without going to the extreme of ring-worlds and dyson spheres.

Imagine an automated, self maintening O'Neill Cylinder that has been in operation for numerous generations. It is possible that the inhabitants may have reverted to some form of feudalistic society .

[atpollard]

... the inhabitants may have reverted to some form of feudalistic society.

Imagine a catapult hurling rocks at the enemy castle located almost directly overhead [the real trick is to adjust for rotation].