The eventual move to the great central plain necessitated the development of canals for transportation and, from the late-19th century onwards, of much larger irrigation and flood-control systems. Small nuclear families occupied villages, comprising a wat and wooden houses on stilts. The pattern of life was governed above all by the seasonal rhythm of the monsoons and by a series of important religious festivals. Many of these festivals were closely associated with fertility and the arrival and ending of the rains. The Thai are now an increasingly urbanized people, with a strong interest in shopping and trade. Thai cookery is considered one of the world’s great cuisines, known for its range of subtle spices and sauces.