Just to clarify, I am pretty sure rationalwiki is not "anti-Islamic".
Regarding, "visiting anything anti-Islamic is haram and forbidden", from what I understand it is forbidden in the sense some scholars of our times have decided it to be practical and beneficial to forbid such an activity and not in the sense that the original sources of Islam directly term this as Haram. In other words, more of a secular prohibition than a religious one.
