It's not a tent, it's a Big Top! Honestly.... ;-)
Well, I think it's technically also a "Circus Tent". But Big Top is a mre fun word.
<pedant>
Technically, it's two words.... ;-P
</pedant>
I think we may have hit upon another of those international differences again.
<nag>well, "phrase" or "expression" would have been a better choice than "two words"</nag>
In the USA, "Big Top" is kind of a... I dunno, "fancy" expression...circus tent is to big top as...major league baseball is to "the big league". Not that that's very international.
I've always thought of Big Top to be shorthand for a circus that does altitude acts such as tightrope performances and flying trapeze, at least, and possibly more complicated acts using large rigs such as motorcycles inside a spherical cage, etc.
Of course, when I was young, I had no idea that the Circus could be anything but a big-top, but nowadays they're all sorts of Cirques and Circuses, and one that can't do high-wire but can do a million good animal acts would still be perfectly entertaining.
Your trapeze photo is great! It has the same dark feel as our circus print of the girl on the horse. Nice work.