Some people believe in the concept of immaculate inception. They say there is a forbidden kingdom where pure maidens reside, forever virgo intacta.
Law doesn't believe in such crap, had stopped to believe a long time ago. He is a doctor through and through.
Some people tell tales about the kingdom of fierce female warriors who take pirates prisoners for their pleasure and then mercilessly kill them, throwing overboard.
Who knows where lies the truth?
When boredom of the long vigil gets him, Law remembers these tales and starts to fantasize. In the morning, however, he feels nothing but disgust.