Skyview Towers are a new addition to the Legend of Zelda franchise, introduced in Tears of the Kingdom. These towers serve a similar purpose to the Sheikah Towers in Breath of the Wild.
Towers will sometimes be open for players to interact with and other times, there will be some restrictions or puzzles to solve before being able to get inside. When inside, the towers will launch players high into the sky where Link will survey the land below. Once the animation is complete, a portion of the map will be exposed for the player to use. Once all of the Skyview towers have been discovered, the player will have the full map of Hyrule exposed.
The large height of these towers and their position, typically atop mountains, make them a great way for players to look out for shrines and other items of significance. Launching in the sky is also a great means of travel as it allows Link to make use of the glider to get over difficult obstacles and quickly glide to a desired location.