The Tama Khola dialect of Limbu (Kiranti, Tibeto-Burman, Nepal) is found to exhibit what has been called "vertical case" ('up at', 'down in') in other Kiranti lanugages, but which is not reported from other Limbu dialects. It appears to be unique among Kiranti languages in distinguishing topographic (uphill/upstream vs downhill/downstream) from gravitational up and down. Thus it has a five-term directional system where other Kiranti languages have a three-term system. The origin of the single locative case marker reported in other Limbu dialects is discussed.