What is this place with 5 altars in Witcher 3?
Solution 1:
According to this Reddit thread, those 5 pillars do not have any functional purpose in The Witcher 3 but serve as a reference to a quest from the first Witcher game
This spot is a reference to one of the quests in the first Witcher game. In it you had to activate an elemental that was frozen in the middle of five pillars, by convincing the nearby druids to create a thunderstorm so you could use a lightning rod to activate each pillar then fight the elemental