Ringworld Contruction

[Wanderer]

Don't forget: you need to send a colony ship (same colony type as your homeworld) to the ringworld, preferably timed to arrive at the same time the construction takes place.

First time I built one I had to sit and admire it for 5 turns whilst I built and brought up a colony ship...

Oh, and having a few population ships ready to deposit a few billion of your race on the thing is a good idea too.