Dungeon

A Dungeon is a game element in the Final Fantasy series, where the player is meant to explore and obtain treasure, while defeating enemies along the way. In the end of it, lies a goal: an artifact to be obtained, a boss to be defeated, or even a cutscene to be seen. Only by accomplishing these objects, the story will progress and unfold. Dungeons are usually accessed via World Map, but in some cases, they are accessed via other smaller dungeons, either by passageways or warp devices, or in some rarer cases, the player is instantly taken to a dungeon due to a plot event.

A Final Dungeon exists in each game: it consists of the area where the Final Boss resides, waiting to be defeated. Most games also feature secret, optional dungeons, that usually either hold precious treasure inside, or incredibly strong Superbosses.

Final Fantasy
In Final Fantasy, each dungeon contains an important artifact and a boss to be defeated, with exception of the first dungeon, the Chaos Shrine, and the [Mirage Tower, which is merely a path to the Flying Fortress.

List of Dungeons:
 * Chaos Shrine
 * Marsh Cave
 * Western Keep
 * Cavern of Earth
 * Mount Gulug
 * Ice Cave
 * Citadel of Trials
 * Sunken Shrine
 * Waterfall
 * Mirage Tower
 * Flying Fortress
 * Earthgift Shrine, an earth-elemental theme optional dungeon ridden with Final Fantasy III bosses, featured in the Dawn of Souls and 20th Anniversary remakes.
 * Hellfire Chasm, a fire-elemental theme optional dungeon ridden with Final Fantasy IV bosses, featured in the Dawn of Souls and 20th Anniversary remakes.
 * Lifespring Grotto, a water-elemental theme optional dungeon ridden with Final Fantasy V bosses, featured in the Dawn of Souls and 20th Anniversary remakes.
 * Whisperwind Cove, a wind-elemental theme optional dungeon ridden with Final Fantasy VI bosses, featured in the Dawn of Souls and 20th Anniversary remakes.
 * Labyrinth of Time, an optional dungeon featured in the 20th anniversary remake.

Final Fantasy II
Like the previous game, almost every dungeon has a boss or/and a key item to be obtained, otherwise, a mere cutscene must be seen. This game was the first to feature points-of-no return. Due to a the existence of a solid storyline, some major plot events occur in dungeons.

List of Dungeons:
 * Fynn
 * Semitt Falls
 * Bafsk Sewers
 * Snow Cave
 * Kashuan
 * Dreadnought
 * Deist Cavern
 * Coliseum
 * Tropical Island
 * Mysidia Cave
 * Leviathan
 * Tower of Mysidia
 * Cyclone
 * Palamecia
 * Jade Passage
 * Unknown Cave, a post-game optional dungeon featured in the Dawn of Souls and 20th Anniversary remakes.
 * Unknown Palace, a post-game optional dungeon featured in the Dawn of Souls and 20th Anniversary remakes.
 * Arcane Labyrinth, an optional dungeon featured in the 20th Anniversary remake.
 * Arcane Sanctuary, an optional dungeon featured in the 20th Anniversary remake.

Final Fantasy III
Final Fantasy III follows the series' consistency, having one boss per dungeon. This game featured optional dungeons for the first time, as well as cutscenes in each of them.

List of Dungeons:
 * Altar Cave
 * Sealed Cave
 * Dragon's Peak
 * Nepto Temple
 * Tower of Owen
 * Subterreanean Lake
 * Molten Cave
 * Hein's Castle
 * Cave of Tides
 * Amur Sewers
 * Goldor Manor
 * Cave of the Circle
 * Temple of Time
 * Ancient Ruins
 * Cave of Shadows
 * Doga's Grotto
 * Ancients' Maze
 * Crystal Tower
 * Dragon Spire, an optional dungeon that holds treasured equipment for Dragoons
 * Sunken Cave, an optional dungeon that holds many treasure
 * Saronia Catacombs, an optional dungeon that consists of Odin's residence
 * Lake Dohr, an optional dungeon that consists of Leviathan's residence
 * Bahamut's Lair, an optional dungeon that consists of Bahamut's true lair
 * Forbidden Land Eureka, an optional dungeon that holds sealed powerful equipment
 * ???, an optional dungeon featured in the Nintendo DS version

Final Fantasy IV
Party members often leave and join the party inside dungeons in Final Fantasy IV.

List of Dungeons:
 * Mist Cave
 * Underground Waterway
 * Antlion's Den
 * Mt. Hobs
 * Mount Ordeals
 * Ancient Waterway
 * Lodestone Cavern
 * Tower of Zot
 * Eblan Cave
 * Tower of Babil
 * Sealed Cave
 * Sylph Cave, an optional dungeon located in the Earth
 * Feymarch, an optional dungeon that leads to the home of the Eidolons
 * Lair of the Father, an optional dungeon that consists of Bahamut's lair
 * Cave of Trials, an optional dungeon located in Mount Ordeals that features new equipment in the Advance remake
 * Lunar Ruins, a long and difficult optional dungeon located in the Red Moon that houses new puzzles, equipment and enemies, available only in the Advance remake

Final Fantasy V
By the time of Final Fantasy V, plot events were more common at the end of dungeons than properly the aquisition of key items.

List of Dungeons:
 * Pirates' Hideout
 * Wind Shrine
 * Ship Graveyard
 * North Mountain
 * Walse Tower
 * Fire-Powered Ship
 * Library of the Ancients
 * Ronka Ruins
 * Castle Exdeath
 * Underground Waterway
 * Drakenvale
 * Barrier Tower
 * Pyramid of Moore
 * Island Shrine
 * Great Sea Trench
 * Istory Falls
 * Gil Cave, an optional dungeon from the second world
 * Castle of Bal, an optional dungeon from the third world, where Odin lies
 * Fork Tower, an optional dungeon from the third world that houses the spells of Holy and Flare
 * Phoenix Tower, an optional dungeon from the third world where Phoenix can be obtained
 * Sealed Temple, an optional dungeon available only in the Advance version, composed by several smaller dungeons

Final Fantasy VI
In Final Fantasy VI many dungeons reward the player with a playable character, and in rare cases, Magicite. For this reason, most dungeons are actually optional. The use of dungeons for paths can also be seen in this installment.

List of Dungeons:
 * Narshe's Mines.
 * Figaro Cave
 * Mt. Kolts
 * Lethe River
 * Phantom Forest
 * Phantom Train
 * Baren Falls
 * Mt. Crescent
 * Serpent Trench
 * Zozo
 * Magitek Factory
 * Cave to the Sealed Gate
 * Espers' Gathering Place
 * Floating Continent
 * Figaro Castle
 * Darill's Tomb
 * Mt. Zozo
 * Owzer's Mansion
 * Cave in the Veldt
 * Cultists' Tower
 * Cyan's Soul
 * Ebot's Rock
 * Dragon's Den, an optional dungeon featured in the Advance remake
 * Soul Shrine, an optional dungeon featured in the Advance remake

Final Fantasy VII
In Final Fantasy VII most dungeons appear as only a passage, and if otherwise, they're most probably optional. Items are rarely obtained in dungeons anymore.

List of Dungeons:
 * Mythril Mines
 * Mt. Corel
 * Cave of the Gi
 * Mt. Nibel
 * Temple of the Ancients
 * Forgotten Capital
 * Great Glacier
 * Gaea's Cliff
 * Whirlwind Maze
 * Ancient Forest, an optional dungeon with several treasure
 * Sunken Gelnika, an optional dungeon underwater with precious equipment

Final Fantasy VIII
Final Fantasy VIII has a rediculous small amount of locations in comparison to earlier installments, so dungeons either end in plot events or are intirely optional. A lot of these are points of no return as well.

List of Dungeons:
 * Fire Cavern
 * Tomb of the Unknown King
 * D-District Prison
 * Missile Base
 * Balamb Garden
 * Great Salt Lake
 * Lunatic Pandora
 * Deep Sea Research Center, an optional dungeon in the edge of the world

Final Fantasy IX
Final Fantasy IX has many dungeons in comparison to its predecessor, and somewhat rewinds to a pattern similar to Final Fantasy V.

List of Dungeons:
 * Evil Forest
 * Ice Cavern
 * Gizamaluke's Grotto
 * Burmecia
 * Path to Cleyra
 * Alexandria Castle
 * Pinnacle Rocks
 * Fossil Roo
 * Conde Petie Mountain Path
 * Iifa Tree
 * Oeilvert
 * Desert Palace
 * Mt. Gulug
 * Ipsen's Castle
 * Earth Shrine
 * Castle Pandemonium

Final Fantasy X
Final Fantasy X hasn't many dungeons due to the fact that the world map has been abolished. However, examples of dungeons are the Cave of the Stolen Fayth and the Omega Ruins, both optional.