GAT; 2x interviews.
Interview 1 (Human Geography): discussion; Interview 2 (Physical Geography): discussion, map interpretation.
Mock interview; personal statement read-over and knowledge; keeping up with current affairs.
Enjoy the time you have there; don't worry about what you're wearing; think out loud.
Remember this advice isn't official. There is no guarantee it will reflect your experience because university applications can change between years. Check the official Cambridge and Oxford websites for more accurate information on this year's application format and the required tests.
Also, someone else's experience may not reflect your own. Most interviews are more like conversations than tests and like, any conversation, they are quite interactive.
Test taken: Geography Admissions Test (GAT)
Number of interviews: 2
Time between interviews: 4 hours
Length of interviews: 20 mins
Online interview: No
Neither interviews asked me anything about my personal statement. My human geography interview focused on my local area, sustainable development and land use. My physical geography interview focused on what I was interested in, climate change, conservation of species. I was also shown a map and was asked to say what I thought was causing changes in the trend shown. It was lot more chill than I expected and not as nerve racking either, all tutors were really nice and more of a conversation rather than interview.
I annotated the example GAT questions then wrote a practise answer for the questions not under timed conditions. I then got my teacher to read it through and give me advice