"Unimaginable scale" refers to something that is so large, immense, or vast that it is difficult or impossible to fully comprehend or imagine its size or extent. Full definition
«The Big World» alludes to the vast, almost unimaginable scale of contemporary Chinese art in the international art scene, but the title also references a large and storied Shanghai amusement park. (dailyserving.com)
We take it for granted, but here on the Niagara Frontier we are surrounded by vast industrial projects of almost unimaginable scale — monstrous factories, massive powerhouses, enormous tunnels, gigantic canals — all crisscrossing around and beneath us. (news.wbfo.org)
At the start of the 3rd millennium AD, thanks to the digital revolution, man's capacity to make knowledge available to an ever larger audience has increased on an previously unimaginable scale. (turbofuture.com)