How many of each type of interior are needed?
Ancestral tombs of House Redoran (mostly west of the Pryai) and House Indoril (east of the Pryai): 5 each
Daedric ruin: one small one here (link is external), originally of a small secluded cult.
Kwama mines (wild): 5
Natural caves with creatures, bandits (especially near roads), recluses and strange things: 10