The Rainforest Kingdom, being very true to its name, is a giant rainforest. It borders the Mud Kingdom to the north, where the tropical forest gradually transitions into a wooded swamp. The forest is very colorful, hot, humid, shady, and rainy, with undergrowth making it difficult to move in many areas.
The Rainforest covers what is supposed to be the haunches (back legs) of the dragon-like continent or the southeast part of the Continent. To the north is the Mud Kingdom. The mountain range borders the Rainforest Kingdom at the west followed by the Kingdom of Sand and the Lost City of Night. The south and east of the Rainforest Kingdom is the vast, unknown ocean. It is possible that a hind-leg peninsula was attached to the southeastern part of the kingdom, but sunk into the ocean sometime between the Scorching and the fleeing of the Old Night Kingdom, possibly due to a tsunami.
Most of the other dragon tribes stay out of the Rainforest, and it was unharmed by the War of SandWing Succession, so it is still very beautiful. MudWings had been wary around that area because of a "monster" (NightWing kidnappers and the howler monkeys modified to make screaming noises) but the problem was resolved shortly. Because they weren't involved in the war, the Rainforest wasn't a target for any of the rival queens or royal families.
RainWing VillageThe rainforest is populated with hundreds of RainWings. They live in a village full of treehouses, fruits, platforms, hammocks, and trees. The roofs of the houses are made of leaves, making it harder to see the houses while flying and looking down. The village is made up of treehouses, connected by vine walkways. The village has three hatcheries, each hatchery holding a third of the village's eggs. Each hatchery has a tightly woven floor and is shaped like a large green egg. The RainWings mix their eggs and raise them as a village, making it unknown who is related to who unless they do a venom test. However, Glory promises to make sure that RainWings know who their kin are.
There is a large treehouse that houses the queen, who until the end of The Hidden Kingdom takes turns with other queens each month. (Dazzling, Fruit Bat, Grandeur, Magnificent, Exquisite, and Splendor were the queens.) There is also a Royal Garden which Tamarin, one of the gardeners, takes care of.
Many platforms and hammocks are between trees for the RainWings' sun-time. The healer's hut, which is close to the sunning platforms, is described to have red berries growing on the balcony, with skylights shining through its leafy roofs. Their houses are made in the trees with leaves as windows and the trees as a natural wall.
At the center of the village is a structure called the Arboretum (which resembles a non-violent version of the SkyWing arena), a huge platform made from woven branches and surrounded by more treehouses, some of which have been set up as fruit stands. It seems to be a meeting place for the RainWings and where many public events take place, such as the competition between Glory and the existing queens for the throne.
The Royal Pavilion is a structure that is built halfway between the NightWing and RainWing villages. It is used for settling disputes and making special announcements to both the NightWings and RainWings, as well as greeting visitors to the Rainforest Kingdom, such as Winter and Qibli (Winter Turning).
The pavilion is built on the branches of a large circle of trees. It rests midway between the forest floor, where the NightWing village is, and the jungle canopy, where the RainWings reside. Glory stated this was to symbolize she is the queen of the NightWings and RainWings. Its roof is made of the same large translucent leaves that are also used as windows in the Jade Mountain Academy library. The center of the pavilion is ornamented by a small dais for Glory, raised only a few inches above the ground, that serves as a throne there. Instead of jewels or treasure as decoration, there are flowers such as morning glories and orchids.
This is where injured dragons are brought. Starflight stayed here for an extended period following the events of The Dark Secret, and this is also where Turtle and Anemone cast spells on Kinkajou that protected her from Darkstalker, healed her, woke her up, and made her fall in love with Turtle (the last spell was courtesy of Anemone).
This is the section of the Rainforest where the NightWings have lived ever since their volcano erupted and the NightWing Exodus occurred. It is the closest part to the NightWing tunnels and has thinner trees. The NightWings have built huts out of leaves and twigs. The RainWings offered to help, but the NightWings, wanting to keep the dignity they had left, refused the offer. Because of this, the NightWing huts are poorly built and tend to leak or collapse frequently. The NightWing village is also very close to the ground and mentioned by Winter to be very muddy. However, during the epilogue of Darkness of Dragons, Mightyclaws uses the power given to him by Darkstalker to help create homes for the NightWings.