RIDDLE 1 - This Killer was collared, but is he now on the loose?
Gadgets used: Line Launcher, Explosive Gel
Approach the area from the east. Make sure that you're on the upper ledge, equip the Line Launcher and shoot at the western wall in the distance #1. Wait for Batman to reach the destination #2.
After reaching the western ledge, turn on the Detective Mode thanks to which you should note that the floor here can be destroyed #1. Equip the Explosive Gel, spray and detonate it. You can jump to the lower room #2.
Completing the above actions will let you reach Killer Croc's hideout (screen above). Scan it.
RIDDLE 2 - This question can only be answered from an unusual perspective. Can you get yourself there?
Approach the area from the east, entering one of the cars #1. Afterwards turn to the north and activate the Detective Mode thanks to which you will find the partial solution of the riddle #2.
The question mark you have found is a reflection, so as you have probably guessed you will have to turn around and examine the windows in the southern part of the wagon. Stand so that you can put the dot and the proper part of the question mark in one frame (screen above).
RIDDLE 3 - BOARD at drive-time? I'm not going to broadcast any more clues!
Search the platform (lower level) for a Vicki Vale billboard (screen above) and scan it.
RIDDLE 4 - Coming back from the dead is cheating on any day of the week.
Find a Solomon Grundy graffiti on the wall (screen above) and scan it.
RIDDLE 5 - It's vacation time. Where shall I go? Somewhere venomous?
Find the Santa Prisca poster on the northern wall of the main station room (screen above) and scan it.