Lake Hylia

Lake Hylia is the largest body of water in Hyrule and is commonly guarded by the Zora people. It has appeared in a number of The Legend of Zelda games, and in both Ocarina of Time and Twilight Princess, it is home to an underwater temple that is guarded by the Zoras. It is possible that the Lake made its first appearance in the original Legend of Zelda as the large body of water found near the center of the overworld map; however, since the lake is never referred to during the game, this cannot be confirmed.

A Link to the Past
Lake Hylia's first true appearance is in A Link to the Past, where it is located in southeast Hyrule and has a network of small caves coming off it. In both its Light and Dark World incarnations, the lake is filled with River Zora who will attack Link upon sight. In the center of the lake is an island featuring a Wishing Well that is inhabited by Venus, the Queen of Fairies, who will upgrade Link's ability to carry bombs or arrows in exchange for Rupees. Outside the pond is a warp tile that grants access to the Ice Palace located in the Dark World's Lake Hylia, which has several ice platforms across the lake.

In addition, the Ice Rod item is found in a cave to the northeast of the lake, as well as the Golden Bee, a bottled insect that can be unleashed to attack foes. The lake itself is fed from Zora's River, which in turn flows from Death Mountain.

Ocarina of Time
In Ocarina of Time, Lake Hylia is located in the southern region of Hyrule and is home to the sunken Water Temple, which is used by the Zoras to worship the water spirits. The lake is made up of various islands, with the largest one bearing a lone tree as well as the pedestal that serves as the warp point for the Serenade of Water. It is connected to Hyrule Field and has an underwater tunnel that serves as a shortcut to Zora's Domain, although it is blocked by ice once Link turns into an adult. All of the lake's water comes from Zora's Fountain, passing through Zora's River, then Gerudo Valley, and eventually reaching Lake Hylia. As such, it is possible to reach the lake by floating down the river from Gerudo Valley. Also on the shore of Lake Hylia are two scarecrows named Pierre and Bonooru, the latter of which helps Link obtain the Scarecrow's Song. Other notable locations of Lake Hylia include the Lakeside Laboratory, where various experiments are conducted to discover the lake's mysteries, and the Fishing Pond, where Link can fish for an unlimited time for just 20 Rupees.

Link first visits the lake as a child while looking for Princess Ruto, where he finds Ruto's Letter encased in a bottle at the bottom of the lake. Later, after the young hero turns into an adult by pulling the Master Sword from its pedestal, Link returns to find the lake almost drained from its rich waters. He discovers that the lake has been drained as a result of Morpha's curse. With the help of Princess Ruto, Link sinks to the bottom of Lake Hylia using Iron Boots to reach the Water Temple and defeat Morpha. Once Ruto awakens as the Sage of Water, the lake is filled with water again, returning it to its normal state. Furthermore, Link can stand on a stone tablet above the Water Temple's entrance and shoot an arrow at the sun when it's rising to have the Fire Arrows appear on the small, lone island.

Four Swords Adventures
In Four Swords Adventures, Lake Hylia is the first stage of the Whereabouts of the Wind, which is the first level of the game. Unlike in the other games where Lake Hylia is one whole lake, Lake Hylia appears here as a series of small lakes connected by rivers. It is located in the eastern portion of Hyrule. The lake area primarily serves to introduce controls and maneuvers. Link learns the many ways to line up to pass obstacles and fight enemies, and it is here that the young hero meets Kaepora Gaebora and Tingle for the first time in the game.

The terrain consists of mainly grassy areas, caves, rivers, and mountainside waterfalls. Among the inhabitants of the area, Tingle can be found beneath a rock in Link's path through the area. At the end of the level, the four Links must fight the stage's boss: Chief Soldier. Upon its defeat, the four barriers must be broken with the Four Sword in order to yield passage to the Cave of No Return. 

The Minish Cap
In The Minish Cap, Lake Hylia is located in the east of Hyrule. The water enters the lake by a river from Veil Falls to the north. To the south is the Minish Woods and to the west Lon Lon Ranch. Stockwell, the shop-owner from Hyrule Town, owns property here where his dog, Fifi, lives alone. As does Librari, the Minish elder of the Royal Hyrule Library. Moreover, Waveblade, one of the Blade Brothers, houses a tree, ready to teach Link sword techniques. David Jr. is also found here. The lake's most important feature is the Temple of Droplets, a frozen Minish-sized temple which serves as the fourth dungeon of the game.

Twilight Princess
In Twilight Princess, Lake Hylia is located on the west side of Hyrule and is part of the Lanayru Province. The lake is home to Lanayru's Spirit Spring, Fyer's Cannon Rides, and Falbi's Flight by Fowl. The Lakebed Temple rests at the bottom of the lake, where Zoras patrol the entrance to the template due to it being a sacred place for their people. Lake Hylia is again fed by Zora's River, which travels all the way from the throne room of Zora's Domain. The only ways to access Lake Hylia is by playing Falbi's Flight by Fowl game, take the Iza's Rapids Ride game, jumping down from outside the South Gate of Castle Town, or by just warping there. Despite this, many Hyrule citizens come to Lake Hylia to send prayers to Lanayru.

When Link first visits Lake Hylia, it is covered in Twilight and has been mostly drained due to Zora's Domain being frozen, which stopped the water from flowing into the lake. Once Link unfreezes Zora's Domain, the water flow returns and fills up the lake, allowing the young hero to visit Lanayru at her spring and obtain the Vessel of Light to collect the Tears of Light of the Lanayru Province. Collecting 15 Tears of Light will make the last Shadow Insect appear in the middle of the lake, which is actually an oversized monster known as Twilit Bloat. The defeat of the Twilit Bloat allows Link to collect the last Tear of Light, thus returning light to the province.

Later on in the game, Link must visit the lake once again to meet with Auru at the tower situated on the west side of the area. Auru hands Link a memo to give to Fyer so that the young hero will be able to reach Gerudo Desert and thus reach the Mirror Chamber.

Lake Hylia is also home to three Pieces of Heart as well as a mini-game hosted by Plumm known as the Fruit Pop Flight Challenge.

Trivia

 * In Ocarina of Time there are 3 claw marks on the tree by the warp pad that Link appears at after playing the Serenade of Water.
 * By entering Lake Hylia through the portal in Zora's Domain on Ocarina of Time, the establishing shot shown everywhere except Hyrule Market would be skipped until it was entered "properly".
 * While never given an actual name, the lake from The Legend of Zelda is very similar to Lake Hylia and could be its predecessor. Likewise, the body of water around Hyrule Castle in The Wind Waker might be a part of Lake Hylia.