One of the hardest boss battles in inFAMOUS: Second Son happens in an instanced area, but apparently it’s not so instanced, as discovered by Reddit user locopelli. Be advised that from this point on this post contains spoilers, so if you didn’t play the game yet, you may want to head back.
The boss battle against Eugene appears to be in its own separate instance, but using the now pretty well known off-map glitch you can find it in the open world, floating over the sea.
It’s unknown if the actual battle happens there, with different environmental conditions that change the sky and the sea, or a designer just used that unmapped area as a sandbox to model or test the build, forgetting to remove it from the finished game.
What we do know, is that those extremely annoying platforms are there, as you can see in the screenshots below.