Finished Arkham Asylum with 100%? I think not! Warden Quincy Sharp's secret room houses the blueprints that lay out Arkham City.
Warden Sharp's secret room is located right off of his office. It's not located on any of the maps and you can't see the weak wall with Batman's detective vision. You can only blow it up with several applications of explosive foam.
Rocksteady Studios lead narrative designer Paul Crocker explains:
"While building
Batman: Arkham Asylum, we placed a number of ‘hooks’ into the game that tie into the ‘Arkham-Verse’. From the beginning we knew that Quincy was a bad guy, and planned what his next move would be. The room obviously ties into Arkham City, but to be fair, we hid it pretty well. We did assume that it would be found eventually and after following forum posts for 6 months or so, decided to announce it in the ‘Game of the Year’ podcast. The fans of the game have been amazing and again, reading the forums, we can see how much they value the efforts we have put into creating the background stories for the various characters and it was great to see all the posts and theories about the secret room once it was discovered. What I think people are really going to enjoy is not just how Arkham Asylum led to Arkham City, but also how the story in Arkham City sheds new light on the events you saw in Arkham Asylum."
Go find it yourself!