Silent City: The Delving Dead was introduced as part of GU61, The War of Zek, and is not yet available on Kael Drakkel. But several of its achievements are listed on the server due to the category it is associated with (Desert of Flame), due to its physical location in the world (Ro). ~ Kaitheel
In addition, Kenn, please put together a list of these achievements for out-of-level instances, and I can pull those achievements from the Kael achievements listing. Thanks!