If you're talking about in twilight princess, there is a lake bed temple. Complete all the steps to the temple. You should eventually end up in an underwater maze. At the end, there is a room with three spider web covered holes in the floor. Cut the one in the middle, fall through, and the boss' key should be beneath you.
check the map at telmas bar. it will mark his location on ur map.
The Hylian field is the big field that you first see when you come out of the Kokiri forest. In it's centre is Lon Lon Ranch, and from the field you can go to Lake Hylia, Gerudo Valley, Hyrule market town, Kakariko Village, Lon Lon Ranch, Kokiri Forest, or Zora's River.
The big key
Warp to Death Mountain. There will be a big, tall rock stuck in the ground. Go over to it and the Midna icon will appear. Talk to her and she will warp it back to the Zora village... just watch what happens from there it's kinda cool.
Find the big key.
the variations of the big goron sword
Throw the nearby bobm-bugs in it.
if your talking about link to the past, at the edge of lake hylia, there is a bombable cave, go inside and you wwill see a big chest. go back outside and bomb the areas to the left until a secret door shows up, go inside and receive the ice rod yays!
That is saria's song
it is in the ice cavern in zoras domain
To catch a 15-pound fish in "The Legend of Zelda: Ocarina of Time," head to the fishing pond in Lake Hylia. Use the fishing rod to cast your line, and bait the hook with a baited lure or a fishing bait to attract larger fish. Be patient and wait for a big fish to bite; once it does, use careful, steady movements to reel it in without breaking the line. Remember, the 15-pound fish is found deeper in the pond, so look for larger shadows in the water.
There are 4 bottles available to obtain in the Legend of Zelda Ocarina of Time and you can recieve them by doing the following: Find the 3 super cuckoos in the super cuckoo minigame at Lon Lon Ranch, Find all of the cuckoos and bring them back to there pen in Kakariko Village then talk to the lady by the pen, Dive underwater near Zora's Domain at Lake Hylia to find a bottle with a letter inside show it to King Zora in Zora's Domain and he will let you keep the bottle, Find all of the Big Poes scattered around Hyrule and show them to the Poe collector in the Market (she's in the first door by the entrance).