A video for this post: some people from the collaborative production game SFZero came together to create a circle of door trilithons in a public but undisclosed location. Later videos show them dancing a victory dance as a policeman approaches, and then discussing the installation with the sceptical but tolerant copper.

The henge turns out pretty well, and its guerilla art quality  gains it points from me. 7½ druids for this daring performance henge!