The Batt family went for drive up Mt Ngongotahā on Sunday.
They were left "gobsmacked" for all the wrong reasons.
"The whole lot of us were going up because the kids had not been up there for a long time, it was Father's Day and we were looking at buying a house up there," Jules Hira-Batt told the Rotorua Daily Post.
They found clothes, cans, boxes, paint pails, carpet, even the bottom of a shower, down the side of the cliff and scattered "all the way down" Mountain Rd.