Here we go: it was my second ever solo circuit flight. My first solo - a couple of weeks before - had only been a single circuit. Just making my third approach, when the FISO announces that the airfield is now closed - all ground movement is to cease, and all aircraft are to leave the circuit for the local area.
Well, what do you do ? I performed a go around, and headed out into the circuit to think about what I was going to do next. I hadn't bought my first map yet, and there wasn't one in the cockpit. I knew a little about the local area, but not enough to fly away and then find my way back, and certainly not enough to find another airfield.
The story goes that there was a bomb scare and the police had requested that nothing could move within so much distance of the suspect package - and this area included the runway. As it was, my instructor was in the control room, explained the situation, and they gave me clearance to land. Best landing I'd ever done, by the way, as I figured I should get it right first time.
Anyhow - some advice. Before you send your students up for their solo circuits : Make sure they have a map and that they can vaguely make their way towards another airfield - preferably someone with an ATC and a radar (for example, as I understand it, if I'd had to go somewhere else, then heading towards and contacting Luton would have resulted in huge amounts of help by their ATC).