Liver 3 (Taichong/Great Rushing) is a very popular acupuncture point that I use everyday in my Chicago acupuncture practice. It is often a sensitive point when rubbed or needled so many of my patients ask me what that point is used for.
You might want to see if you find the point sensitive on yourself. It is located on the top of the foot in a depression between the first and second metatarsal bones. You can get some guidance from the picture of Liver 3 to the right. The reason Liver 3 is used frequently in spite of the sensitivity is because it is a terrifically useful point.
Investigators compared two acupuncture points on the foot, Liver 3 and Stomach 44 with a nearby sham acupuncture point and found that both Liver 3 and Stomach 44 consistently elicited specific brain responses. When Liver 3 was stimulated, it activated the visual cortex and other areas of the brain that affect the central nervous system. Pretty cool!