Angel Land, known as Angeland (エンジェランド Enjerando) in Japan, is a kingdom where, a long time ago, gods and humans lived together in harmony. It consists of four separate "stages": the Underworld, Overworld, Skyworld, and the Palace in the Sky. Angel Land was once co-ruled by Palutena, who administered light, and Medusa, who ruled darkness. Eventually, Medusa's hatred of humanity drove Palutena to transform her into the ugliness seen in her soul and exile her deep in the Underworld.
To get revenge, Medusa teamed up with the evil creatures in the Underworld and formed an army to invade the Palace in the Sky. Palutena's Army could barely defend due to the Underworld Army's surprise attack, and the Three Sacred Treasures were quickly lost in the battle. Most of the heroes from Palutena's army were turned into stone by Medusa, and Palutena herself was imprisoned deep inside the Palace in the Sky. The once peaceful Angel Land was turned into a land of darkness ruled by Medusa and inhabitated by terrible monsters.
Weakened, Palutena asked for the help of the angel, Pit, who was held captive deep underground in the Underworld, giving him a Bow. Due to the low security in the Underworld at the time, Pit manages to escape and proceeds to obtain the Three Sacred Treasures and rescue Palutena in Kid Icarus.
Pit also travels through the various stages of Angel Land in Kid Icarus: Of Myths and Monsters to bring peace to the land.
Not much is known about Angel Land itself, but there are many kinds of environments and regions in this realm, such as lakes, forests, mountains, caves and volcanoes. During the invasion of the Underworld Army there are Underworld monsters in practically every location of Angel Land that Pit has to destroy, with a boss in some locations and Fortresses.
Angel Land was renamed Skyworld in the English version of Kid Icarus: Uprising, and in the game it appears to be only a large area from the heavens ruled by Palutena instead of a larger kingdom that also includes the Underworld and Overworld. Palutena's Temple is presumably a renamed Palace in the Sky.
The Super Smash Bros. for Wii U stage Palutena's Temple is named Angeland in the Japanese version.