It’s a funny question coming from someone who regularly writes about tall buildings and long bridges, but I think the photo above, of the west facade of Building A at the Brooklyn Army Terminal, justifies why I’m asking. At the beginning of the first (1977) Star Wars movie, there’s a moment where a large spaceship is going past the camera and it just keeps on going and going. Spaceballs, the 1987 parody of Star Wars, deliberately exaggerated that moment for laughs. That’s as close as I can get to what it’s like standing next to a building almost 1000 feet long is like. It’s a very different sensation than standing next to a 1000-foot tall building because of the differences in the way we perceive height and length.
Building B, which is the same length as Building A but about one-third wider, was the largest building in the world by floor area when built. These huge buildings were constructed entirely in reinforced concrete in 1918-1919, which is itself somewhat amazing, given the state of concrete analysis and design at that time.
There is no single answer to the title question, of course. Everyone will have their own, and people may have more than one, or their opinions may change over time. But standing near the long facades of these two buildings and looking down them is actually disorienting because of their size. That’s big, in my opinion.