Sleepless Waterfall
From Zelda Wiki.org
The sleepless waterfall is a waterfall at the end of the Zora River in Ocarina of Time. The waterfall lies as the final obstacle in the river Link must pass before entering Zora's Domain, of which the entrance is just behind the waterfall itself. The waterfall (and therefore, Zora River itself) flows from Zora's Fountain where Lord Jabu-Jabu dwells. It is possible to view the drop-off of the waterfall from Zora's Fountain, but unlike the trip from Gerudo Valley to Lake Hylia, jumping down the waterfall is impossible (without glitching) due to a series of stakes blocking travel.
Spoiler warning: The following contains key plot or ending details.
The waterfall is not accessible directly, instead requiring that Zelda's Lullaby be played (as indicated by the triforce marking on the ledge just in front of the waterfall, and Navi's hint).
A Link to the Past
Theory Warning: Be advised that the following article or section contains unconfirmed, fan-made theories or speculation.
In A Link to the Past, it is possible (but not certain) that the waterfall where the Flippers are obtained is the same Sleepless Waterfall as in Ocarina of Time due to their similar placement, although Zora's Fountain is absent from the top and Zora's Domain would be unreachable behind the waterfall.

