Generically, a sorcerous means of transportation, usually consisting of two or more pools of water which are linked, such that one can enter one pool and emerge from the other. They are usually persistent, though they can be done short-term.
Kuan-Xi has been building a series of Water Gates, primarily the Tahiti Water Gates. Her teacher, Shen Gao has also built a number, mostly to his childrens' houses. At present, that includes the Hidden City, Cedar Haven in the Qin Chao Steppes, Flowering Resolution in the Jade Taiga, and the pagodas of Iron Mountain, where his second son is on a pilgrimage.