Mirror Lake (カガミ湖, Kagamiko) is a lake north-east of Ransen. It gets it's name from it's unique trait of perfectly reflecting it's surroundings, while holding a solid surface. Walking on it produces ripples and hands pressed to the surface will become wet, though it is impenetrable and therefor safe to venture onto without fear of falling through. There is a cave on Mirror Lake, though it cannot be entered through normal means.
While the lake itself is quite beautiful and mysterious, the cave is by no means attractive. It's not deep, and it only goes back so far, though it is very dark, damp and musty. It holds a foul wind to it, and gives off the vibe of something awful.