 During the Middle Ages there were only 6 towns in Finland (Turku, Porvoo, Naantali, Rauma, Ulvila and Vyborg), with wooden buildings growing organically around a stone church and/or castle.Historian Henrik Lilius has pointed out that Finnish wooden towns were on average destroyed by fire every 30–40 years.They were never rebuilt exactly as they had existed before, and the fire damage offered the opportunity to create new urban structures in accordance with any reigning ideals