The Pillars of Zanash are a set of ancient architectural remains found in the vicinity of East Ardougne. The Pillars are mentioned only in the Tourist's Guide to Ardougne, found in the real-estate agency within the city. There is some uncertainty regarding their identity.
The Pillars are not referenced by name anywhere else in-game. The tourist's guide claims they are west of Ardougne, although no structures can be found fitting this description. The only ruins in the vicinity of the city are found north and east of the city. One set marks the entrance to the ancient Temple of Ikov, found north of Ardougne. The other can be found above the entrance to Witchaven Dungeon east of the city. It is very possible that the pillars used to be part of the previously mentioned ruins. Nothing else can be found in RuneScape that explains this.