Visit to China of less than 72 hours - do I need a visa, transit type or none at all?

I am a citizen of the United Kingdom, but living in France. I intend visiting Beijing in June, including a trip to the Great Wall at Jinshanling. I will arrive at 09:30 on 9th June and will leave at 11:15 on 11th June, a total of 50 hours. I will be arriving on a British Airways flight from London and returning to London. What kind, if any, do I need?