Forest Haven

The Forest Haven, comprised of two main islands, is found in The Wind Waker.

Entrance to the Haven
It is home to the Koroks, who once took humanoid form and were called Kokiri. They are watched over and protected by the Great Deku Tree. The main island takes the form of an enormous dead tree trunk, out of which flows a stream. Link must traverse the stream, defeating Boko Babas and Octoroks, in order to enter the haven.

Upon first arriving at Forest Haven, Link finds the Deku Tree infested with ChuChus. Once they are defeated and the Deku Tree restored, the place becomes serene and calming.

Main Area
The Forest Water flowing from inside the Forest Haven has special purity, and it may be bottled and used to invigorate the Korok's saplings. However, this purity does have a time limit, and is present only in the water found within the walls of the tree. Hovering above the water, several fireflies can be found, which may be bottled and used towards the creation of the Deluxe Picto Box. The interior of the island contains many Baba Buds which Link must use to reach the highest branches of the Great Deku Tree, where he will be rewarded with the Deku Leaf, a vital tool used to reach and explore the nearby Forbidden Woods.

Outer Area
The Forest Haven actually consists of various islands. The aforementioned Forbidden Woods are located on the second-largest island, west of the main area, and can be reached by landing first on a taller southern island surrounded by a cyclone. The Nintendo Gallery can be found hidden on a lower island north of the main area, and can be reached by hovering with the Deku Leaf from a high spot (and later by simply climbing a ladder). Finally, there is an abandoned island southeast of the main area that houses a Treasure Chart. Each minor island can be reached by hovering from a corresponding exit of the main area, although all of them can be accessed from the exit that leads mainly to the Forbidden Woods, with varying difficulty.

Finally, there is a hidden Piece of Heart under the sea that can be located and collected by opening a Treasure Chart from a lonely man living on Windfall Island.

Theories
The distinctive, lilting theme heard at the Forest Haven is similar to Saria's Song. It is theorized that the Forest Haven may be formed from the mountain tops of Kokiri Forest, or even the remains of the Great Deku Tree from Ocarina of Time on the outside, with the younger sprouting Deku Tree seen in Ocarina of Time as an adult, within the Forest Haven itself.

Trivia

 * When connected by lines, Dragon Roost Island, Forest Haven, and Greatfish Isle form a large triangle; the three Triangle Isles, when connected by lines, creates a smaller triangle attached to the larger one - the entire image created is that of the Triforce, and the Tower of the Gods exists at the dead center of the symbol.