The so-called Harley Heads are more breakable objects that you have to destroy in Batman: Arkham City. Unlike the Tyger Security Cameras and Joker Balloons though, they are fortunately found only in the Sionis Steel Mill, so you will not have to spend time searching and gliding over multiple districts.
These collectibles appear as Harley Quinn mannequins with inflated heads. They are pretty hard to miss. They also contain voice boxes that you can activate to listen to her dialogues. That, however, will not get you the collectible.
To destroy a Harley Head, you have to aim a Remote Electrical Charge at her head. That is the only way to advance your Riddler Challenge. Speaking of which, destroying three heads amounts to one riddle. Most players began to wonder why their challenge count was the same after destroying the first head.
Batarangs and Glue Grenades do not work against Harley Heads.
Where to find all Harley Heads in Batman: Arkham City?
There are a total of 12 Harley Heads (for four Riddler Challenges) to destroy in the Steel Mill which contains both the Joker’s and Harley’s hideout. The latter is exclusive to her Revenge DLC though.
You may encounter a glitch where you destroy a Harly Head and it still shows up on the map as undestroyed. To solve this, either quit the game and come back later or progress further through the story.
You will gain access to the Steel Mill early on as part of the main storyline. However, you will not be able to explore every area inside until the end of the game. We, hence, recommend waiting until you have beat the game before going there to get all of its collectibles.
That being said, there are several ways to get inside the Steel Mill depending on where you are in the story. Once you beat the main story, your only way inside will be through the flaming, broken roof.
Did You Know
You will have to enter the Steel Mill as Catwoman to get her Catwoman Trophies.
Harley Head #1
The first Harley Head in Batman: Arkham City we will cover is located at the northern end of the Sionis Steel Mill – inside the Manager’s office. More specifically, it’s in the northwestern corner of the office.
Harley Head #2
The second Harley Head is located below the Manager’s office – the Loading Bay. You will find the mannequin in the northeastern corner of the Loading Bay, next to a big set of screens.
Harley Head #3
This Harley Head is located in the Basement Level of the Sionis Steel mill – next to the north wall of the small section that connects the freight elevator to the Boiler Room here.
Harley Head #4
The fourth Harley Head is located in the Boiler Room of the Steel Mill’s basement. You will find this at the entrance of the main hall of the room.
Harley Head #5
The fifth Harley Head is located inside the Assembly Line room. It’s right next to the door connecting this room to the Joker’s Fun House.
Harley Head #6
This Harley head is located on the western wall of the Assembly Line Room. It’s right to the left of the door leading into the Smelting Chamber.
Harley Head #7
The seventh Harley Head is located in the northeastern corner of the Smelting Chamber. It’s in front of the east wall at the ground level where you see sparks from the smelter.
Harley Head #8
The eighth Harley Head in Batman: Arkham City is located inside the Smelting Chamber as well, this time in the west of it. This one is just to the right of the door leading into Cooling Tunnel D.
Harley Head #9
This Harley Head is located inside Cooling Tunnel D. You will find it on the right, next to the crates, just as you enter through the door which connects it to the Smelting Chamber.
Harley Head #10
This Harley Head is located a little to the south of the previous one. As you get into the Cooling Tunnel – D from the Smelting Chamber, take your first left and you will see it right across the stairs leading into the lower section.
You can also find one of the Riddler’s Riddle Solutions here.
Harley Head #11
This Harley Head is located inside Cooling Tunnel B, just to the left of the small door connecting it to Cooling Tunnel D, beside an open locker.
Harley Head #12
The last Harley Head is located in the southernmost part of the Sionis Steel Mill. It’s next to the wall right opposite the exit in Cooling Tunnel B.