History in Brief:
Lanzhou then served as a center for trade and industry throughout the dynasties and continued to be an important center for commerce.
Sightseeing in Lanzhou - What to See & Do::
One should also sample a bowl or two of Lanzhou's famous Lanzhou Beef Noodle Soup or 兰州牛肉汤面. This cuisine has been exported all over China as fast/street food but you should be sure to try them in their birthplace. Lanzhou's most famous outlet for these yummy noodles is Mazilu. But don't expect to find them for dinner. Lanzhou locals eat noodle soup for breakfast and lunch but not dinner.
Walking the Yellow River is another something to do in Lanzhou. There are several parks along the banks, including the Waterwheel Park. It's a good place to see local residents relaxing and strolling.
Most people find themselves in Lanzhou for business or on their way to other Silk Road destinations, such as Dunhuang. If you do find yourself in transit there, make sure you visit the museum and then don't feel bad about moving on.
An excellent source for more detailed sightseeing as well as general city information is this website: Redefining Lanzhou. It is one of the best in-depth city guides (outside of Shanghai or Beijing) for China that I have encountered. The site recommends a number of sights and walking tours, none of which I had time to do while I was there (but wish I had!)