RIDDLE 1 - My intellect towers above yours, Batman. I wonder if you'll ever solve this riddle?
The "official" location of this riddle is very misleading, as you don't even have to be in the Bowery. It's only important to scan the Wonder Tower (screen above), the highest building in the whole Arkham City. If the game keeps telling you that the object is too far away, try zooming in the view. Notice! Whether the Tower is untouched or already partially destroyed doesn't matter, you can complete the riddle anyway.
RIDDLE 2 - Arkham city is not a place for the rich or famous, Bruce Wayne never felt so wanted.
Find the Bruce Wayne wanted posters (screen above) and scan them.
RIDDLE 3 - The feuding families always sit down to a good meal. Will there be a massacre?
Find the entrance to the Maroni's Italian restaurant (screen above) and scan it.
RIDDLE 4 - You're a dummy if you don't try and buy one.
Find the entrance to the Magic and Props shop (screen above) and scan it.
RIDDLE 5 - Cowboy, trilby or bowler? Hats off to anyone brave enough to try one on.
Find the hats shop (screen above) and scan the entrance.
RIDDLE 6 - Studies have shown that if you're not on your best behavior, you'll come out crazy. How Strange?
Find the gate with the TYGER logo (screen above) and scan it. It's not important whether it's locked or partially raised.
RIDDLE 7 - Do you need to look SHARP to campaign for change?
Find the campaign billboard (screen above) and scan it.
RIDDLE 8 - You don't want to be caught off-guard in this place, do you?
Get to the room with the hostage (from the south) and scan him (screen above).
RIDDLE 9 - This question can only be answered from an unusual perspective. Can you get yourself there?
Gadgets used: Remote Electrical Charge, Cryptographic Sequencer + Cryptographic Sequencer Power Amplifier + Cryptographic Sequencer Range Amplifier
After reaching the Arkham City Processing Center entrance, use the REC to open the nearby door #1. It will let you reach a partially flooded room. If you now turn towards the passage through which you came here and turn on the Detective Mode, you should note an incomplete question mark #2. In order to solve the riddle, you have to find the missing dot.
Stay on the balconies and approach the locked grate east of here. Equip the Cryptographic Sequencer and use it on the control panel in the distance #1. Start hacking it and create the password #2.
Enter the newly unlocked room. Use the Detective Mode to find the missing dot. Afterwards you will just have to stand properly, as shown on the two above screens. Remember that the main part of the question mark and the dot have to create a whole.
RIDDLE 10 - Was the writing on the wall from the moment you entered?
Get onto the balcony adjoining the Arkham City Processing Center (screen above).
Examine the southern part of the balcony to find a plate informing of the date on which Arkham City was opened. Zoom in on it (screen above) and scan it.
RIDDLE 11 - You don't have to be crazy to shop here, do you?
Stand in front of the big gate (screen above).
Zoom in on the JEZEBEL CENTER sign (screen above) and scan it.