Cameron Blockhouse, Military defense structure in Whanganui, New Zealand

The Cameron Blockhouse is a military defense structure in Whanganui featuring double-skinned totara wood walls filled with clay and topped with a corrugated iron roof. The construction displays typical colonial-era military architecture built with sturdy local materials.

John Cameron bought the Marangai property in 1841, but only around 1868 did he commission the blockhouse, fearing an attack by Riwha Titokowaru after the Māori leader's victories in south Taranaki. Te Kooti's raid on Poverty Bay around the same time heightened settler fears. The privately built redoubt was listed as a Historic Place Category 1 on 10 October 1994.

The name Marangai comes from the property John Cameron bought in 1841, and the blockhouse stands on that land. Its tōtara walls and clay infill show how settlers used local timber and earth instead of imported materials. The building was never attacked, so it survives as a privately built redoubt rather than a military site.

The blockhouse is accessible year-round for visitors wanting to examine the military architecture up close. It is located in Whanganui and relatively easy to find, though checking local information about the exact location before visiting is helpful.

The blockhouse is one of the few surviving privately built redoubts from the New Zealand Wars; most others were military works. John Cameron raised it on his Marangai farm around 1868, after Titokowaru's victories in south Taranaki and Te Kooti's raid on Poverty Bay. It was listed as a Historic Place Category 1 on 10 October 1994.