Photos by Leslie Adkin, 6 June 1938. “Probable site of Pa-o-Toata shown on J.D. Climie’s map of the area 1880-1884 on the Waikanae River within the confines of the Tararua Range. The semi-isolated tongue of high level terrace evidently the spot.” (Alexander Turnbull Library)

It indicates the Mangakotukutuku Stream which is a tributary of the Waikanae River.  The NZ TopoMap here lets you zoom up on the area.