Poro-O-Tarao (or Porootarao)[1] was a flag station on the North Island Main Trunk line, in the Waitomo District of New Zealand.

Between the watersheds of the upper Mōkau and Whanganui rivers, the NIMT enters Poro-O-Tarao tunnel under Tihikārearea hill, before descending the Ōngarue valley.

[2] Work on the Ohinemoa section (Poro-O-Tarao tunnel to Te Kawakawa, south of Ōngarue) started by December 1897.

[2] Although the station closed for goods in 1976, it remained open for Ministry of Works traffic, during construction of the new tunnel, until 10 November 1980.

[2] The Public Works Department awarded a contract to J. J. O'Brien for the Poro-O-Tarao section (including tunnel) in August 1885.

However, the sacred grove was felled before tohunga could remove the tapu, and was said to have caused people to die of illnesses that traditional Māori medicine could have cured.

[8] It goes through Mahoenui Group soft sedimentary rocks, including landslides; the cause of hummocky ground and many small scarps.

The southern approaches to the new tunnel are largely unstable landslide debris, formed of silty clay with rock fragments.