The district has a coastline onto the Solent to the south and Southampton Water to the east.
The Banham Commission had recommended that New Forest should become a unitary authority in 1995, but this was rejected by the government.
The whole district is also covered by civil parishes, which form a third tier of local government.
The district council appoints four of its councillors to serve on the 22-person National Park Authority.
The oldest part of the building was originally a large house, which was purchased in 1954 to become the offices of the New Forest Rural District Council.