I have never heard about those things but they do look pretty much the same as what I did! That's quite funny My idea was just to paint some old concrete tubes that are perhaps remains of some construction site. There were lots of those things in Poland during communist era, sun tunnels never crossed my mind! Thanks for those link, they went to my reference folder already.
it's a concept from the book "Roadside Picnic". or it can be chernobyl's exclusion zone. for me it's a space that once used to be man's land but it's not anymore. it's got traces of human presence but it's not for humans anymore. kind of