The main reason most people in the North Island have heard of Palmerston is when an irate Mainlander corrects them for failing to qualify Palmerston North as such. It's something of a point of irritation for people from Otago, including my parents.
The original Palmerston is an hour or so north of Dunedin; originally a rural hub, it's declined to a small town looking for things to do; one of the things it's hit upon with which to achieve this is a butterfly and bird house. We noticed it on the way through to Dunedin coming down, and decided to nip up and have a look.