Kaikawaka Reserve is a small scenic reserve south of Rangiwahia, rated 5.0 from 3 Google reviews. It is reached by turning off Rangiwahia Road onto Miangaroa Road and continuing onto Wairaki Street.
The website describes a reserve of about 5 hectares with a loop of roughly 20 minutes, through native bush with old kahikatea trees. The track is a pest-control track rather than an official Department of Conservation track, and the site says it may be walked. The entrance is marked by an information sign. Camping is not allowed, and visitors are asked to take all rubbish away. Reviewers say the track is marked with tape on trees, so tell someone your plans before you go.
For a short bush loop with old kahikatea south of Rangiwahia, this reserve is worth a visit with care on the track.