Silk has a history of some 4,500 years in China, so they have become adept at producing many different types of silk, as well as dyeing it and weaving different patterns into the fabric. Suzhou is famous for its silk production. In the Suzhou Silk Factory you can see a display of the life-cycle of the silk worm and demonstrations of how the silk is harvested from the cocoons and eventually woven into fabric. It is quite astonishing to learn that one cocoon can produce about 2 km of silk strand, and that several of these strands are twined together to make a single thread. The process is so slow and painstaking; it comes as no surprise that genuine hand-made silk articles are so expensive.