This Trophy is not to be missed upon playing story through. *** Spoiler - click to reveal ***It is the second Gate in order, required for you to open up. You are required to open a small series of Gates. Go with Yorda to the specific room where there is a pressure plate, and use your combined weight to open one Gate. Then pick up a wooden stick and light it up on any fire source around - then be swift about it, and light up the candles on the left and right of another Gate. It will open. You have to do this also with a third Gate there, before the Trophy will be awarded to you. Be wary that you have to pull some triggers that are around there as well. And you have to take Yorda up the watery room to progress in story - also, you have to turn the Reflector until it is fixed in its new directional place intended.
ou require to open West Gate in order to progress in story.