It is one of the deepest lakes in all of Shijuren, and it is fed from snow running off the mountains that encircle it.
From the Books: "He grinned. 'They’re to be enjoyin’ their view of the lake, and I’m not to be blamin’ them as she is bein’ a beauty and cold and sweet. You should be drinkin’ some fresh water from the springs on the mountain in that there cask that was to be bein’ brought over this dawn from a boatman who sometimes is to be comin’ in here when he can.'
He paused to shake some grain back into its bag before continuing. 'In truth, I’m to be thinkin’ the water is bein’ a part of why me ale is as good as there is, and you’ll be walking the same route that cask will take when it’s emptied, exceptin’ turnin’ at that road which is easy enough to see even though there’s many a road down there.'" - ALMD, p. 44