For the normal Ciar Dungeon, go here. Ciar Hardmode Dungeon is accessible from the altar in the room behind normal Ciar Dungeon. It's much more difficult than the regular version. You can drop any Ciar pass, except for the Beginner and Boss Trial passes, onto the altar to enter the hardmode version of it. Pass limits do not matter; for example, you can bring as many partymates as you want even with a "for One" pass. Players must be total level 250+ to enter it.