I saw this as a fairly small child, on British daytime TV, and I was born in 1982, so I don’t think it can have been any later than 1990.
It was an animated film (I *think* film rather than series, but I only really remember one scene, so I guess it could have been an episode of a series, but I feel like it was a one-off thing, either theatrical movie or made-for-TV “special”) which I remember as having a very beautiful, captivating art style – very lush, green, detailed landscapes, a lot more “naturalistic” than most cartoons at the time. Looking back it “feels” very Japanese and I’m tempted to think it could have been an early Studio Ghibli production.
I remember the setting was a small village in a post-apocalyptic world, but a long time, maybe hundreds of years, after the fall of the previous civilisation. The village was quite idyllic, but closed-minded, the older generation discouraged children’s curiosity about the past. There were ruins of the “old world” around, including the wreckage of a giant robot on top of a cliff or mountain. I don’t think it was something like an EVA or Gundam that a human would have piloted, more like The Iron Giant.
The protagonist was a young girl who was kind of an outsider and disapproved of by the adults because she was curious and liked to wander on her own. She had some kind of artefact (my memory is fuzzy on this) that allowed her to fly/float/levitate (possibly she needed the wind to help as well). She used it to fly up to where the old giant robot was, and when she touched it, its eyes glowed and it started to power up and come “alive” again. She was scared and fled back to the village.
I thought for a while that it could have been “Castle in the Sky” (1986) from reading a plot summary, but I watched it when Netflix had all the Ghibli movies and it didn’t fit, though there were some similar enough elements that made me wonder if I had combined bits of it in my memory with something else. Any ideas?