So they're going to many mosques not one?
Grammatically, yes. msikiti = mosque, misikiti = mosques. Add the "-ni" locational suffix and you have "to (or in) the mosques". Why the sentence is written that way is another question. ;)
Perhaps the mosques have stunning architecture and they are touring them? ;)
Audio says "Wanaenda msikitini", which it accepts as a typo. The "-ni" threw me off because that has not been taught prior to this.