Ok, thanks. So maybe I'll just stick to using 'вокруг', as it seems to be more current, and a tiny bit more versatile. Not sure why I chose 'кругом' anyway. My vocabulary choices often seem a bit random to me, in hindsight.
он (не был там) > Его там не было:- I hadnt thought of его as genitive in this sentence, it makes sense, whereas thinking of as accusative doesnt.