This American-style blockhouse is one of very few of its type remaining in New Zealand. It was erected in 1860 in response to a fear held by local settlers that the conflict between Māori and the Crown over the disputed sale of land at Waitara, Taranaki, would escalate. . A double-skin timber-clad frame with shingle infill was constructed to provide protection against rifle fire. Loopholes were also built for defenders to return fire. The blockhouse was surrounded by a much larger defensive earthwork. The earthwork was flattened to form part of the school playing fields that now surround the blockhouse.
A small militia occupied the blockhouse. However, the feared attack never eventuated and they left the blockhouse in 1861. In 1867-1868 it was used as a police house, courthouse and residence until 1880, and was declared an historic reserve in 1916.
In 1927-1928 the building was substantially repaired and windows added on the inner side of the L-shaped structure. In 1980 the blockhouse and the accompanying land was classified as an historic reserve under the Reserves Act 1977. Soon after that the New Zealand Historic Places Trust was appointed to control and manage the blockhouse.
From 1953 until the late 1990s local boy scouts and girl guides used the building. Today, the blockhouse serves as the headquarters for a service club.