This is about 7 cake layers, measuring at around 10" tall. I learned some lessons on this, but I'm pleased with the results. I should have added supports for every two layers, but I just had the dowel through the middle (my father made the very stable structure).
I started with 4" and 5" cakes, and carved to get a more gradual cut in at the bottom. The word Guinness and the harp were cut out of fondant, though I would have had better results with gumpaste. I painted on the rest with luster dust and food coloring. The cake is covered in dark chocolate fondant, and ivory. My DH loved it, and was very happy with his birthday cake.