Some theologians think Christ went to Tartarus to proclaim his victory but not to release them. This was the holding tank for those angels who cohabited with women in Genesis.
Others think He went to Abraham's bosom to proclaim His victory over Satan to all the Old Testament saints including the thief on the Cross.
The other view is that He did go to Hades to proclaim His victory and give all who died without the Salvation of Sacrifices in the Covenant, a second chance to accept His Gospel. (They never heard it or the Law the first time: i.e.: A chinaman who lived at the time of Abraham.) This would include Socrates, Plato, etc.
From Luke 16 we see that Sheol had two compartments which were separated by a great gulf.
