Nimbus Land is a floating kingdom on a massive cloud where cloud-people live in Super Mario RPG: Legend of the Seven Stars. It is ruled by King Nimbus and Queen Nimbus, who have a son, Prince Mallow. Nimbus Land also refers to World 6 of the game, and includes the level Nimbus Land itself, as well as Barrel Volcano.
The giant cloud of Nimbus Land is attached to a vine accessible from Bean Valley, the only known way to access it from the ground. The palace of King Nimbus stands in the center of the town. Normally, it houses many statues and birds, of which the king is fond of both, and the citizens of Nimbus Land are free to enter. During Valentina's attempted usurpation, however, the palace is sealed to the public and its halls are filled with monsters.
In the castle, (while the stronghold was under the control of the usurper queen Valentina), Birdo was first seen as an egg named Shelly who was cared for by Shy Away, who intended to use the newborn Birdo as a weapon. When Shy Away saw Mario, she quickly abandoned his post and fled, leaving Shelly exposed. Mario could then speak to the Birdo inside Shelly, who would request for Mario to play with her.
For a long time, Prince Mallow was missing. Valentina, however, pretended she found the prince during a plot to become queen of Nimbus Land. 'Prince Mallow' was actually Dodo, a large bird, but the population of Nimbus Land was convinced for a while that he was the true prince. However, Mario discovered the plot. The real Mallow was traveling with him. They, along with the other members of their party, stop Valentina and Dodo and rescue the king and queen.