A quick edit
before the guide : since the Trials of Gnomus DLC the entrance to the Chamber of Gnomes is opened. Simply get out of your safe area, go to the middle of the backyard, plants - to your right, zombies - to your left from the center is the entrance to the sewer. Enter it, go straight, then down the slope, when you're close to the fish, turn left, keep going down the slopes.
Eventually to your right you'll see chests and the entrance to the Chamber. Enter, wait a few seconds and enjoy your achievement. Remember, you'll still need the gnomes for another achievement.*
Alright, boys and girls, this will be quite a long explanation, for those who prefer textual guides.
So, for this achievement to unlock, you'll have to find the Chamber of Gnomes. This is done in few steps. Let's begin. Step 1 : ---
You need to find a gnome. One gnome. So there is a chance that some of you already found him by lurking through the map and enjoying the views. If not, than the closest ones are :
--- either you open the garage in plants base, turn left, it's on the table. To pick it up, you need to stand close enough, press
and hold it for a second.
--- in zombie base, if you exit your Stats Room, turn immediately right and go to the wall, the gnome is inside of a small opened coffin. Step 2 : ---
Once you have a gnome ( or more, this doesn't matter ), go to the flag location. If you're a plant, at a flag turn 90 degrees right, if you're a zombie - 90 degrees left. Keep on going to a small opened space with a fountain. Right behind it you'll see a public phone with an exclamation mark. Approach it and listen to the voice in the phone. Doesn't make sense? That's because it really doesn't. But you just started the next phase. Step 3 : ---
Now comes the hard part. You will need to collect 9 gnomes. Let's start with the easy ones. ---
Pick a Superbrainz ( or a peashooter ) and go to the soccer field. It's on the dock side of the map ( left for zombies, right for plants ). Behind the right side (peashooter balloon ) of the scoreboard, very high, is a gnome. With Superbrainz you can just jump, hold
in the air and collect it.---
Right from the last location, go to the docks. Jump down on the right side through the gap in the fence ( coming from the soccer field ), inside of a big pipe, beyond the bars, you can easily see another gnome.---
From this location go to the sewers. If you don't know how to enter - get back on the street from the docks, one of the back entrances will be right in front of you. Can be easily seen because there is a lot of green toxic waste around it. Once you're in, take an immediate left and keep going straight. Behind the bars of a door you'll another gnome.
---------- Next set of gnomes requires story progression ---------- ---
Finishing the first set of quests for zombie side will reveal an entrance to Dr. Zomboss secret lab. Pick soldier as your character, fall though the door. Honestly, for me this was the trickiest to get. Once you're inside turn around. On the left side of the rock is a gnome. Basically this is a suicide jump - press and hold
has to be synchronized with your position in the air. Might take few tries, so be ready for that.
Or - you can use the Imp's jetpack ability in order to jump on the rocks ( courtesy of NutriWhip ).
When you start doing quests that are connected to new characters, each room you visit will have a gnome. To gain entrance to the next room you'll need to finish quests for the character whose room you chose to enter. So - ---
Citron room : once you entered, look straight and to the left, easy to see.---
Kernel Corn room : once entered, get up the stairs on the left, go straight until you hit the wall, turn and look to your right.
--- Rose room : before going up the first stairs, look to your right. Behind the railing there is a fountain, and behind it on the wall is a hidden square button. Shoot the button to reveal a gnome where the statue was. ( courtesy of NutriWhip )---
Superbrainz room : go straight once entered, behind Superbrainz, jump on a higher platform, he's behind the statue.---
Captain Deadbeard room : to the right of him the is a small bedroom, next to the bed, on the right side.---
Imp room : once you exit the portal, make a few steps forward, look to your right, he's in the car.
For now the hard part is over.Step 4 : ---
Go back to the same public phone, see the exclamation mark? Answer it again. The voice will guide you to go to the docks and pick up the "key". Go to the docks and realize that the "key" is a gnome bomb.
Pick it up and go back to the closest sewers entrance. Get inside, turn right and over the boards until you can *safely* go down a level. Opposite of Craze Target Range you'll see a spot for your bomb, so walk over it. Almost done now!Step 5 : ---
Once the gate is no more, enter, go down, down, down - well, you can see the entrance already. Just don't forget to open two chests ( free chests! ) and get lots of money and two items. Once you enter the hall, achievement pops! Yay!
P.S. Look at the walls and realize how many more gnomes you need to collect.
Hope this will make it easy enough for you to unlock this one for you. Have fun!!!