2/ The island was named Christmas Island 🇨🇽 when it was sited by an English sea captain on 25 December 1643.
Christmas Island is an external territory of Australia 🇦🇺, but for historical reasons it has its own ISO 3166-1 code: "CX", a good example of why our geocoding API returns both ISO codes and a "country_code"
https://en.wikipedia.org/wiki/States_and_territories_of_Australia#External_territories
3/ Christmas Island 🇨🇽 only joined Australia 🇦🇺 in 1958, when the United Kingdom 🇬🇧 transfered it from the Colony of Singapore in exchange for a payment of $20 million.
#geoweirdness