How do you get into the intensive treatment building in Batman Arkham Asylum?

To access the Intensive Treatment Building in Batman: Arkham Asylum, you need to progress through the game until you reach the area near the entrance. You'll encounter a gate that requires you to use your Batarang to hit the control panel and unlock the door. Additionally, make sure to follow the main storyline, as certain objectives and encounters with enemies will guide you toward the entrance. Keep an eye out for any environmental clues that may assist you in navigating the area.