Magic Lamp - Velen
Location: Elven Ruins/dungeon
Quest Giver: Keira Metz
Other Requirements: Complete Wandering in the Dark - don't leave the ruins
This quest is only temporarily available, immediately after you complete the Wandering in the Dark quest you'll be able to accept this one from Keira if you agree to help her. If you don't agree to help her or you leave the ruins then this quest fails, forever lost to time.
First thing you'll have to do for this quest is to follow Keira into the next room and use your Witcher Senses to inspect the door. There's a riddle on it that will clue you in on the proper order to light the statues to open the door. The order you need to light them in is; third statue, second statue, fourth statue and first statue; the second statue is to the right of the door. To make things easier I have included a picture below.
You will find the Magic Lamp in the very next room and your quest will update to leave the ruins. But wait, there's more! In the same room you found the Magic Lamp in go west and climb up the rocks. You will come across a Place of Power, a Golem and a Hidden Cache of Treasure. Both of these are marked on your map and can be really confusing trying to find them if you don't know they're underground and you're up above ground looking.
For those of you stumbling into this guide googling about the Place of Power near Lake Wyndamer; below is a map location of the entrance that leads into the dungeon for this Place of Power.