Where would aliens make a public reveal?

A place with a live global audience makes sense as a thought experiment: perhaps a major international gathering or a public broadcast. It would be hard to miss, and the setting would make the message feel aimed at everyone rather than one country.

I’d expect the sky over a densely populated area, not a single landmark. A clear, sustained display visible from lots of places would give people a chance to observe the same thing independently, instead of relying on one dramatic clip.

Maybe they would start with scientists instead of a spectacle. A signal that several observatories could check would be less cinematic, but it could give the public a way to distinguish a serious claim from a rumor or a misleading video.