Millith Ironheart is an Eorzean explorer that appears in Final Fantasy XIV. She is the granddaughter of famed explorer Roddard Ironheart and an explorer in her own right. During the time before the Sixth Umbral Era, Millith tasked herself to catalogue and explore Gelmorran ruins. Then, situated at Buscarron's Fold within the Black Shroud, she dealt with Adventurers to obtain information from the variety of Dungeons beneath the surface of the realm.
Following the Seventh Umbral Calamity, around the dawn of the Seventh Astral Era, Millith had moved on to cataloguing incredible sights across Eorzea, which she kept in a diary. One day while in the Carline Canopy in New Gridania, Millith was accosted by Eral and left her diary behind in her haste to abscond from his advances. The book was found by Naoh Gamduhla who asked an Adventurer to return it to Millith.
The Adventurer managed to track down Millith at Apkallu Falls in Old Gridania, where she recognised the Adventurer as a kindred soul, one who had a "burning desire to bear witness to all the wonders around [them]", and gifted them a sightseeing log of their own, that they might explore and find the locations of vistas across Eorzea.
Millith is proud of her family's legacy as explorers and is passionate about exploring and mapping the underground dungeons and ruins that lie scattered across Eorzea, focusing on Gelmorran cities, claiming that "that which hides beneath" the land "[holds] the greater mystique", in contrast with her brother's explorations of the aboveground. Despite this she is also immensely fond of hearing others tell their stories of amazing sights throughout the land then visiting those locations herself and cataloguing them.
Behind the scenes
Despite her initial portrayal as focusing on the underground ruins of Gelmorra, being the achievement NPC for dungeons in the initial release of the game, Millith in A Realm Reborn is an NPC that gives the sightseeing log, an incentive to explore the overworld. This is in contrast with her brother Nedrick, who unlocked exploration achievements in the initial release, and is instead a quest giver NPC that leads to various optional dungeons in A Realm Reborn.