We tell you where to look for the well during the side quest Mistress of the Iron Wood «in the game Assassin’s Creed Valhalla
This is the first quest in Jotunheim, where you will get after the quests in the world of Asgard. Get to the quest marker and then look around. There is nothing here — just a round slab. Stand on it and look south. You will notice a staircase leading to the rocks with drawings. Read what is written on the rock at the very top of the stairs. Turn around and see that the same round plate has disappeared, opening the way into the well.
Otherwise, you just have to collect some plants inside the cave, next to the waterfall.