There is a sprite of an Octorok from the original The Legend of Zelda located on the bottom right of the Trousers of the Hero.
Breath of the Wild started it's development in 2011 as an open world Zelda Game for the Wii U, originally planned to be released in 2015. The release was later delayed to 2016 after developers conceived of new gameplay options they wanted to include. This release date was then further delayed to 2017 so that it could be released simultaneously on Nintendo's next platform, the Nintendo Switch.
Monk Oman Au's name and the shrine of Oman Au are both anagrams of Aonuma. Eiji Aonuma is the video game designer, director, and producer who works for Nintendo as the series producer and manager of the Zelda series.
You can hear the recorder sound from the first The Legend of Zelda in shrine areas.
The game is the first 3D game in the series to include manual jumping, though this feature was first planned for The Legend of Zelda: Ocarina of Time.
In shrines, after placing the Sheikah Slate to download runes, Hylian text begins to run down the stalactite above it. Portions of the text have been translated to read "NOW LOADING DO NOT TURN OFF YOUR" and "ALL YOUR BASE ARE". The latter phrase is a reference to Zero Wing, a 1989 game infamous for its horrible English dialogue that spawned the iconic phrase "All your base are belong to us".
According to series producer Eiji Aonuma, to date, The Legend of Zelda: Breath of the Wild has a larger number of people working on the game than on any of Nintendo's previous titles.
The opening scene, Spoiler:when Link emerges from the cave where he awakens and overlooks the valley from the Great Plateau, was made to reference the illustration of Link overlooking the cliff from the original The Legend of Zelda.