I’m reading a book now, and the main character maps several rooms to find secret rooms in them. I think this should happen more often in Pathfinder!
Knowledge (Engineering) and Knowledge(Dungeoneering) are considered class skills for you. As you explore underground locations or building, you may make a map. If you do, you may use either Knowledge(Engineering) or Knowledge(Dungeoneering) instead of Perception to find secret doors or rooms.