Flask is the infamous "bar behind a Coke machine" on Shaanxi Nan Lu. Past the admittedly cool entrance is a standard bar with post-industrial design and, unfortunately, not much ventilation -- it gets smoky in here. The place stays busy, and they do not allow patrons to stand. Cocktails are decent, and run about 60-100rmb. Lots of whiskey, naturally. It's especially popular with a Taiwanese and overseas Chinese crowd. Music is Top 40. It's a decent place to take tourists, but for a night of drinking, you've got better options.