"No es una cosa bien conocida."
Translation:It is not a well-known thing.
My dictionary (University of Chicago Spanish Dictionary) translates "conocido" as adj., p.p. "known; well known; m. acquaintance" (and they have used and marked wrong in different places the translation of conocido as acquaintance). It seems redundant to say "bien conocida" unless it is a proverbial expression. Native speakers care to comment?