This image is the aviary at London Zoo, designed by Cedric Price. The photograph is from the book Re:CP, p42. It looks like it could unfold and fly away at any moment.
He made another, for rare birds that couldn’t be let out, because the land underneath the aviary would be progressively destroyed, with bird shit and so on.
It’s described in an interview in Re:CP: “The aviary itself walked about [the land] very slowly without frightening the birds. […] the birds, the inhabitants, would move the city, not some mechanical device.”
So the birds would perch and push the sides and so on, and the thing would move because of that. There’s no robotic engine moving the thing around.
I mean, you look at that, and you think: that’s meant to move. That’s meant to walk. You can see it, strolling over London.