A Chao Garden is a place where Chao can be raised. Chao Gardens were first introduced in Sonic Adventure. Most gardens can contain up to eight Chao at time except for the Tiny Chao Garden which can only contain one.
In Sonic Adventure and its remake, there are three separate Chao Gardens for each Adventure Field. Each garden will have a VMU port, GBA port in DX, as well as two warping platforms that will take you to another garden. By use of the VMU port, a player's Chao can be transported to Chao Adventure. The GBA ports in DX can be used to transport Chao into a GameBoy Advance Game Pak, name a Chao, or to say "Good-bye" to a Chao by releasing it into the wild.
The first Chao Garden is located in Station Square inside the hotel. It can be entered through the first elevator. The garden looks more like a deluxe hotel suite rather than a garden. The floor is made of marble and there is 2 fountains surrounded by water where the Chao can swim. There are two Chao eggs when the player visits for the first time. On the far side of the garden, there are two large doors. Behind these doors is the entry way to the Chao Races.
In Sonic Adventure DX, the garden has one fountain surrounded by water and there is the addition of the Black Market near the front door.
The second Chao Garden is located in the Mystic Ruins near in a cave near Tails' workshop. A trolley must be taken to get there. This garden is complete with ancient ruins and a lake with a water fall. Like the other garden, there will be two eggs when the player visits for the first time.
In Sonic Adventure DX, there were some minor aesthetic changes. The water was made much more shallow.
The third Chao Garden is aboard the Egg Carrier in the main room. The player must spell "EGGMAN" using the lighted panels on the floor. A door will open and the player can use the warp plate inside to get to the garden. Notably, the Egg Carrier garden is the largest of the gardens. It is set on a beach. For some reason, there is a large missile sticking out of the ground. In the center, there is a mountain with some kind of base on top that cannot be entered.
In Sonic Adventure DX there were some minor aesthetic changes. The ocean is not as deep and it cannot be ventured in as far as it could be in the Dreamcast version and the mountain has a lower altitude.
Like Sonic Adventure, Sonic Adventure 2 and its remake also has three different Chao Gardens. They can be visited through Chao World after the player obtains a Chao Key from a Chao Container on one of the action stages. Only one garden is available from the start while the other two need to be unlocked later.
The first Chao Garden is a basic garden. It has two fruit baring trees and a lake complete with waterfall. Near the back is a VMU port where the Chao may be transported to Chao Adventure 2. Behind the waterfall is the entrance to the Chao Races.
When the player first visits, there will be two Chao eggs ready and waiting to be hatched.
In Sonic Adventure 2: Battle there were a few changes. The garden now has three trees instead of two. Flowers were added in as well. The cave behind the waterfall was dubbed "Chao Cave". Omochao is inside with detour signs. One direction leads to the Chao Races while the other leads to the new Chao Karate.
The VMU port became a GBA port. It has basically the same functions as the ports from Sonic Adventure: DX (Note: Sonic Adventure 2: Battle was before Sonic Adventure: DX). The only difference is that this version does not have the naming feature, as that can be done via the Fortune Teller in the Chao Kindergarten. Instead it has a transportation system which allows Chao to be moved from one memory card to another.
After the player raises their first Hero Chao, the Hero Garden will become available. A staircase in the Lobby will take the player up the the Hero Garden. This garden is much larger than the basic Chao Garden. The garden is given a serene theme and is set high in the heavens. There is a river complete with a bridge. The river flows from a marble fountain situated in the middle of the garden. On the left is a white altar, a perfect place for Chao to test their flying abilities.
There are two fruit-bearing trees. These trees look slightly different from the ones in the basic Chao Garden. The fruit they produce are much lighter in appearance. There is a VMU port to the right of the garden. It is decorated to fit the theme of the garden.
When the player first visits, there will be a Chao egg.
In Sonic Adventure 2: Battle, the layout of the garden was changed. The river and the bridge were removed making the fountain area into a closed in pool. An extra fruit tree was added as well. When the player visits for the first time, there will be two eggs rather than one. Likewise, the VMU port was converted into a GBA port. Unlike the VMU port, the GBA port did not receive a special decoration.
After the player raises their first Dark Chao, the Dark Garden will become available. A staircase in the Lobby will lead the player under the floor and down to the Dark Garden. This garden seems to be the largest of all the gardens. This garden is given a spooky theme and is set in darkness. The ground is white and there are tombstones lining the walls. To make the place even creepier, the water is given a crimson hue, making it appear almost blood-like. To the right is a tiny mountain that can be climbed. At the top is a sort of grave yard. Besides being a mountain, there is a hidden cave inside it that can be entered through the water way. The walls of the cave has strange drawings on it. In the center is a cauldron filled with skulls.
The fruit trees in this garden look drastically different the the trees in the other gardens. They appear to be almost dead and they produce a red fruit that looks like a raspberry. The VMU port is placed on the left of the garden. It is decorated to fit the theme of the garden.
When the player first visits, there will be a Chao egg.
In Sonic Adventure 2: Battle, the layout of the garden was changed. The mountain and the secret cave were both removed. In their place was a dead-looking tree with a cage attached to the branch. An extra fruit tree was added as well. When the player visits for the first time, there will be two eggs rather than one. Likewise, the VMU port was converted into a GBA port. Unlike the VMU port, the GBA port did not receive a special decoration. Interestingly, it does still have the same sound effect when a Chao is placed inside.
Both Sonic Advance and Sonic Advance 2 have what is called a Tiny Chao Garden. Unlike their Adventure counterparts, these gardens can only carry one Chao. A Chao can be brought in by either getting a free egg from the market or transporting one from Sonic Adventure: DX or Sonic Adventure 2: Battle. The Tiny Chao Gardens from both Advance games are exactly the same in appearance. The only difference is that one of the mini games is different between the versions.
The Chao Garden in Sonic Chronicles: The Dark Brotherhood serves as more of an item screen than a walk-in location as in the Adventure games. Chao Eggs in Sonic Chronicles are found in the levels, and hatched chao can be equipped to a character in order to modify their combat statistics in some beneficial way. The Chao Garden simply serves as a menu screen from which appropriate chao can be selected.