Cardiff is a dream though, if you can get to that one

I think its proof of exit and entry you need. And make sure you have everything you need as a paper copy in hand. When I went to that one, they were really difficult because all my paper work was online, they said they didnt have time to use email as part of my appointment, and getting the visa took about three attempts. It was my first time getting a visa though, so I was probably naive, and things hopefully have changed since then.