Final Fantasy XIV is an interesting MMO in that it doesn’t allow for modding support. A lot of other popular genre titles, such as World of Warcraft, allow for “quest helper” add-ons and the like, so that folks can easily find their way to more cryptic locations that aren’t so obvious.
Much like the Mystery Miners quest, here’s another quick guide for a mission that might give you some trouble down the line. Note that everything above the warning is vague, including the header image, which is not in the same location as the quest.
[Mild location spoilers below.]
Source: Destructoid Final Fantasy XIV Shadowbringers guide: City of the Ancients quest