Yeah, I had to resort to those maps (the ones you find in-game mind you!) to find all of the Riddler's challenges. The one I struggled hardest with was a single trophy hidden away on a small island in the middle of Gotham Bay. All the others were pretty straightforward. I can't even remember the one you are referring to, to be honest. I must be getting old... I'll try to take note during my next playthrough (doing it on the hardest difficulty is the final achievement I've yet to attain).
Mind you, I actually am not an achievement-hoarder due to its inherent futility. This game was fun though, and I wouldn't mind a second playthrough AT ALL.
Actually the most fun for me in that game is the fighting in the challenges. I get an enormous kick of making huge combo's (although I still haven't hit the triple-digit mark. Again, I must be getting old.)
Finally, why on earth would you have a hard time picturing me playing as the greatest detective? Too out-of-character for me? Remember that we're talking in one of the geekiest corners of the net, here. In effect: I grew up on video-games, my friend - even though I am and always have been a moderate consumer... I do still miss out on some sorely-needed sleep on occasion.
