Return to Cell Blocks
All items listed here can only be obtained when returning to the zone with certain tools.
Blackest Night Chest
Return to the spot where you found Penguin cages #4 and #5. Use the Line Launcher to zip to a hidden ledge to the left. There's a WayneTech crate up here.
New 52 Chest
Return to the vent with the shock stick thug and head straight left. You'll reach an open room with two spots susceptible to the Gel Launcher overhead. Blow them, then grapple to the ledge with the ladder on it. Use the Batclaw to yank out a vent across from this ledge, then crawl through to find a WayneTech case.
Penguin Cage #18, #19
After battling through the showers, you'll grapple across the courtyard to a series of catwalks. Exit through the lower right door to find two more cages inside this connecting room.
One Million Boots
Now backtrack through the door and grapple to the ledge above it. From here, glide across the left gap, then glide back to a lower ledge on the right. Tucked away back here is a WayneTech crate.
Penguin Cage #20
When you exit the courtyard via a Gel Launcher blast through the wall, look for another cage around the corner.
Blackest Night Belt
This is found when exploring the Arkham wing, nearing the climax of the game. After dropping past the electrical nodes, you'll be near a spinning fan. Use the upgraded Gel Launcher to slow the blades, then crawl through. Inside, use the Line Launcher to cross the gap and reach a WayneTech chest.