Arelium clocktower Located in Arelium. Probably even older than early 1996.
Arelium sewers Located in Arelium. LQ19 "Sewer Ring". Originally BatCity sewers, very old area.
Bards Located in Shadowkeep.
Civilized fighters Located in Arelium.
Civilized mages Located in Arelium.
Club Sarnath Located in Arelium. Originally by Kultamarja, apparently Tedra recoded and expanded on it.
E'siris E'siris, the ethereal city that can be used to cross realms. Resides on the "continent" of Nexus. LQ47 "Master Hunter".
https://tnsp.org/maps/esiris.html
Folklorist Located in Arelium. AQ "Folklorist road trip".
Infizinity Located in Arelium.
Mage Located in Arelium.
Merchant Located in Arelium. The designs for Merchant guild were codified around late 1996. As with many older guilds, lots of people have worked on the guild code during the years, not all listed here.
Nithem's dungeon The actual area of Nithem the Lich, only accessible through special means.
Reaver catacombs Located in Rilynttar. Old area originally by Firefox, converted and reopened by Juggelo 16.02.2004. Might have been in the game as early as 1992.