Shuffle the 12 new tiles with the land tiles. When you draw a tile with a Wachturm, place it according to the known rules. You can place a meeple on the tile, but only on the city, road or as a farmer. You cannot place the meeple in the tower. If a road or a city is completed, you first count the bonus points given by the tower. Then you get the normal points. The farmers don't get any points from a tower. Each tower gives a different bonus.