entity_id,period_id,confidence,rationale,source_id,review_status
ENT_NORR_NIFLHEIM,PER_NOR_VIKING,high,"World of mist and cold in the north, containing the spring Hvergelmir and the root gnawed by Níðhöggr; in Gylfaginning the primordial counterpart to fiery Múspell, and sometimes conflated with the realm of Hel.",SRC_PROSE_EDDA,reviewed