It's about a hundred meters from JY Square (Lahug) going up to Nivel Hills. On th right side of the road, you will see an old house with a parking lot in front, lots of trees, and the house is kinda elevated. There's no signage outside so you will have to look carefully, or you just might pass it by. If you reached Cosmopolitan, then you definitely passed it by already.
Anyway, i'm still trying to get hold of a sketch of the location. Will post it here as soon as i have one.