Cache is located just past the waterfall, off-trail, hidden from waterall-seekers with hopefully no bushwacking necessary.
Should be a quick jaunt approximately 0.1m but watch out for Weeping Willows!
Keep an eye out for boaty, fishy muggles too. The cache is huge so it will be hard to miss and hopefully magical for those wizards and witches brave enough to seek this one out. (If the cache gets muggled, I will try to come up with something else creative.)