 The fernery has been constructed in an old quarry in part of the cone.The duck ponds lie in the northern sector of the explosion crater, which is breached to the north with a small overflow stream.The Auckland Domain volcano, Pukekawa, is one of the oldest in the Auckland volcanic field, and consists of a large explosion crater surrounded by a tuff ring with a small scoria cone ("Pukekaroro") in the centre of the crater.