Added more. Correct me if I put a private map in here.
Public Maps:
Lobby3 (new main):The current entrance for PCB’s classic server.
Flatgrass:One of the primary guest maps. Flat and full of grass.
Guestcity:The other primary guest map. City layout with portals for quick trasportation.
InitiateCityBuild: A road-layout similar to guestcity, only bigger lots. For Initiates and up.
Buildercity:Similar to flat grass except it’s for builders and up.
Advcity:Similar to guestcity except it’s for advbuilders and up.
Spleef:The PCB classic arena for the game of spleef.
War:The PCB classic battle-ground for war.
Pixel:A map dedicated to pixel art.
Bigcity:A city suited for notch himself. Just be careful of the lag.
Newbigcity:The newer version of Bigcity.
Arena:An old arena, flat and dry.
Ctf:A capture the flag map.
Castles:Unknown if public or not. Great landscape.
Desertbuild:An map used for building in a desert landscape. Amazing view.
Deserttown:A unused map for desertbuilding.
Water:A map for water building. Very wet.
Fall:A tall map made just for falling.
Showcase:Not for building in but to display great works of…block art or buildings.
Fallgame:What looks to be an old version of spleef.
Flamecity:Amazing atrium. No idea if public.
Funfunfun:What looks to be an old version of run.
Funnybuild:What looks to be a map for sculpture building.
Futurecity:What looks to be an unused map for future building.
Gangwarfare:A variation of war.
Globe theatre:No clue if it is the globe theatre because of blocks placed on the spawner. Ops only map.
Guestcityfun:Unknown, for ops only.
Guestcityoverflow:Unused map for guestcity overflow.
Gunfight:Tree filled map.
Gunwars:Yet another map for war.
Gunwars2:Cleaned up version of Gunwars.
Heaven:A pure white map.
Hell:Similar to heaven but black and red and with better landscape.
Hardcorespleef:A harder version of spleef. Sides are removed.
obstaclecourse: An obstacle course.
Please post if you know about one not on this list.