I've found a cheap flight from Korea to Australia with China Southern Airlines but it involves a 15-hour connection in Guangzhou, overnight.
I'm pretty sure that as an Australian I need a visa and that there's no visa on arrival at this airport.
But then again I've had a few flights on other airlines which included an overnight stay in a hotel operated by the airline, even on fairly cheap tickets.
So where should I expect to be able to sleep during my night in Guangzhou?