In 1848, William White was appointed as the first resident Magistrate in Mangōnui. He worked out of his own offices originally (next to the present police station) but moved into an official building in the 1870s. A report dating back to the 1880s noted that this building was too small and was deteriorating rapidly.
The present Mangōnui Courthouse was built in 1892. Made of kauri, it replaced the original deteriorating courthouse, which also housed a bonded store and customs house. The Mangōnui Courthouse remained in use until 1948 when the court function moved to Kaitaia. Since then the building was used as a police station up until 1968 when it then passed into the hands of the Lands and Survey Department.
It became a historic reserve in 1980, and is now administered by the Department of Conservation in partnership with the Mangōnui Courthouse Preservation Society.
In the mid 1900s, DOC archaeologists carried out an excavation at the back of the Courthouse property prior to a new shed being erected. This determined that the property had been in part covered by soil some time in the 1960s. Removal of the soil material has uncovered a large rock retaining wall, open drain, and a pebble/shell backyard.
The courthouse is architecturally and historically significant, and may be unique in New Zealand as it has an intact surrounds, which dates back to the 19th century.
Over the years, sewage, water, power and telephone connections were made to the building. An old shed at the rear of the property was condemned and removed, and a replacement was built, containing storage and a toilet to make the property more user friendly to the public without affecting the main building’s historic fabric.
The Courthouse today is in good condition following a raft of remedial work over the past few years. Work completed included painting, wall repairs, interior refurbishment, installation of a sprinkler system, and reconstruction of a storage shed/outhouse at the rear.
The Courthouse now houses a permanent exhibition of local art and craft which is open year round.