"These places are very famous."
Translation:Ces lieux sont très célèbres.
Ceux is a pronoun (i.e replacing a noun), referring to several people. It basically means "Those" in the sense of "the ones who...". E.g. "Ceux qui portent un masque ont moins de risque de contracter le virus" (Those who wear a mask have fewer chances (less chance?) to get infected by the virus).
Endroits is fine as a translation for places.