The harbour's mouth is towards the northern end of Great Exhibition Bay.

[2] The harbour was an important location for the kauri gum digging trade in the latter 19th and early 20th centuries, as some of the highest quality kauri gum could be found around the harbour.

[3] The white sand of Kokota Sandspit, at the southern head of Parengarenga Harbour, has provided a source of high purity silica sand for glassmaking.

While smaller or lower purity deposits are found elsewhere in Northland, the Parengarenga area holds the region's largest silica sand resource by far.

[6] The water is a habitat for Green sea turtles and dolphins, while Orca, and Pilot whales visit the adjacent areas.