[#5] Location 5: Aviary (Botanical Gardens)
Inside the control room which was being guarded by one of the inmates.
[#6] Location 6: Flooded Corridor (Botanical Gardens)
Requirements: Line Launcher
You can get to this area after you've unlocked the Line Launcher. Destroy the teeth before you talk to Poison Ivy in her chamber.
[#7] Location 7: Glasshouse Entrance (Botanical Gardens)
Find the teeth once you've already talked to Poison Ivy and when you're on your way back to Arkham East.
[#8] Location 8: Flooded Corridor (Botanical Gardens)
Destroy the teeth before you start a fight with Ivy during your second visit to the Botanical Gardens building.
[#1] Location: Botanical Glasshouse (Botanical Gardens)
Requirements: Explosive Gel
Proceed to the lowest level and use your detective mode to locate a weak section of the wall. Plant the gel and look for a ventilation shaft after the explosion.
[#2] Location: Glasshouse Generator Room (Botanical Gardens)
Requirements: Cryptographic Sequencer, Cryptographic Range Amplifier
Proceed to the upper balcony once you've eliminated all the inmates. Stand close to the barrier and use your sequencer to hack into a control panel from a larger distance. Once the field has been shut down enter the room and look for the trophy to your left.
[#3] Location: Flooded Corridor (Botanical Gardens)
While you're exploring the vents wait for a possibility to turn right (screenshot #1) and eventually you'll get to the treasure.
[#4] Location: Abandoned Chamber (Botanical Gardens)
Proceed to the lowest level while in the northern section of the room. Turn south and press the crouch key to go through a small tunnel (screenshot #1). Keep moving south until you find the trophy.
[#5] Location: Abandoned Chamber (Botanical Gardens)
Explore the central area of the chamber and locate a movable floor piece (screenshot #1). Use this opportunity to enter a small tunnel and head forward to find yourself in an area with a trophy.
[#6] Location: Abandoned Chamber (Botanical Gardens)
Start off near the doorway to the next room (screenshot #1). You should be able to notice a new platform in the distance and you'll have to glide towards it. Once you've landed make a few steps forward and press the action key to grab the ledge (screenshot #2). Move to your left until you get to a small waterfall. Climb up, turn around and perform a jump towards a metal balcony. From there you should move to your right. Use a Batarang on a nearby rope (screenshot #3) which will allow you to use a new metal platform. Keep heading forward until you find the trophy (screenshot #4).