White Orchard is the best place to get the Power Overwhelming achievement, which requires that you have all five of the Place of Power bonuses active at the same time. There are six Place of Power stones, all within easy ride of each other, in White Orchard. You only need five of them, though. Starting at the Yrden stone, ride anticlockwise and activate each stone in turn. Check out our guide if you need a map to help you.
Video: Power Overwhelming
The Witcher 3 Guide 