In order to arrive at the tower, you need to do a few things. After activating the six statues, you need to make three shapes on the mechanical bird. Consult the journal for the shapes. After making them, you will get the gear part. Please remember to grab the architecture set for your collection. Have Jane put gear in the box to get it to open. Inside, you will see a pocket watch. Put that into the mechanical bird and have that activate the gate. To get the gate open, you need to slide some stones to expose the glyphs underneath in order to press them. Here is something to help you. The tops of the sliders have the little symbols, and they can be seen through the little holes. If you line one up and the little symbol is exposed, it means that the slider is in the right position. Do that for the others and you will see the glyph through the big holes (on the sliders themselves) and click on it. Do this for 4 sets of sliders and the gate will be opened. Go through the gate and a cutscene where Jane calls for her grandad will play. When that is done, the achievement is yours.