If you start in Hamilton, New Zealand and duge directly through the centre of the Earth you woudl arrive in Cordoba, Spain. If you went to 11 other points and did the same you would emerge in 11 more countries (Portugal, France, the UK (Gibralter), Morocco, and via various Islands owned by New Zealand: Algeria, Niger, Nigeria, Chad [opposite the Cook Islands], Central African Republic, Libya, and Cameroon. The colours indicate how many countries are opposite the coloured country (New Zealand has 12, France has 12, the US has 7, Canada has 2, Mongolia has 1).
I will probably have something up tonight.