Hyrule Is the world within the Zelda Series. It appears in most all Zelda games, some notable games that don't include Hyrule as the main location are: Link's Awakening, Majora's Mask, Oracle of Ages, and Oracle of Seasons.
While the history of Hyrule is often shrouded in mystery, it is known that it changes drastically over centuries from game to game. In The Legend of Zelda: Ocarina of Time, Hyrule is seen in its earliest state. It is a vast kingdom filled with millions of inhabitants and a wide variety of races, including Hylians, Zora, gorons, and Kokiri.
Hyrule holds numerous areas of varying climates and geographical configurations. There are mountains of ice and fire, wide fields, thick forests, a vast desert, a thriving river, and a quiet lake. Over time, the locations of these areas shift, but they still exist throughout the ages.
Some specifically important landmarks found throughout Hyrule include Death Mountain, Lake Hylia, the Gerudo Desert, Kakariko Village, Hyrule Field, and Zora River. These common areas have reappeared through the various games in the series.