The goal: Visualise the wireless network links of New Zealand.
The data's available in the Radio Spectrum Management database, available from http://www.rsm.govt.nz/ in MS Access format.
https://github.com/mhansen/nzwirelessmap-fetch contains code to fetch the Radio Spectrum Management database and convert it to JSON format.
You can browse the map generated at http://wirelessmap.markhansen.co.nz/.
My source code is MIT licenced.
The data in the Radio Spectrum Database is Crown Copyright, sourced from Radio Spectrum Management For copyright terms, see RSM's copyright page.