I read this book as a teen, and just finished a re-read of it. Not all SF published in 1970 holds up, but I thought Ringworld did, for the most part. There is a current of both sexism and paternalism running through how the female characters are portrayed, sadly not unusual for SF of that era.... The next novel, Ringworld Engineers, came out in 1980, by which time Niven may have progressed beyond some of the problems with female characters. I don't know, since I never read the rest of the Ringworld books. So my question is: are they worth reading?