The forest consists of two parts. The first part is full of tall and old trees, with their network of roots everwhere. The other part is the ancient castle that the royal family of Soleanna lived in until the accident during the Solaris Project. The latter is guarded by the priests who offer trials, and the ones who complete them will be allowed access to the castle through an Eagle. The forest is also shown to be in a mountainous area, as there are several caves in the enclosing mountain walls. In both ends of the Forest there are two doors that connect to either New City or Castle Town.
The Forest was originally the site of the previous castle of the royal family of Soleanna, until the accident during the Solaris Project ruined the whole castle, leaving the Forest and the ruins as just a place for sightseeing. In Sonic's story, Sonic the Hedgehog first came to the Forest after defeating the Egg Genesis, where he escaped into Tropical Jungle with Elise. However, he later returned to reach Kingdom Valley, after completing the three trials given by the priests.
In the Last Story, both Elise and Sonic were going through the Forest. However, Mephiles used his Chaos Emerald to distract them, and from behind, he impaled Sonic and killed him. After the final battle with Solaris, it is unknown what is the state of the forest is as the incident during the Solaris Project was erased from history.
The first one is floating near the bridge that leads to Castle Town.
The second medal is over the ledges in front of the cave.
In the building under Kingdom Valley's mirror in one of the archways. There is a bridge to the right of the three trials area that leads to the third medal.
The fourth medal is between two trees in the right hand side of the Tropical Jungle entrance area.
In the forest heading to the gate to New City, it is on the right hand side by a rock.
The first medal is floating in the air near the top of one of the large rocks in the large grassy field.
It is floating to the left of the blue pillar in the three trails area.
In the building under Kingdom Valley near the left door. There is a bridge to the right of the Three Trials area that leads to the medal.
It is in a branch of the forest tree closest to the large grassy field. To reach it, hit the Spring on the ground next to the small tree to get on top of a dead tree. Now face the tree with the Silver medal in it and jump into the leaves. Once the player gets just below the leaves, tap the Chaos Spear button rapidly to hang in mid-air to spot the Silver Medal, then use the Jump Dash toward it.
In the area of the Forest near the gate to New City, behind a rock, nearby the constructed bridge.
It is the last Town Stage that Sonic is able to enter, as he must complete his entire Episode before he is allowed to enter the area (except during the short time when carrying Elise in it.)
Of all the Town Stages in the Game, it is the largest and as such one of the emptiest in the entire game.
If one causes a glitch to get Sonic into the area early, an area could be found in the center containing the 2-Dimensional objects that are used during the Race with Sonic Man and other Highway side-missions. There is nothing else one can do here, as the doors do not show up nor do level entrances if one does this glitch.
Of all characters to enter it, Shadow is the only one to not go through the Trials of Soleanna in order to reach his version of Kingdom Valley.