The Citadel

To enter the Citadel you must be on the 'Evidence' quest given by Sarakki the Notary in Britain

To gain access to the Peerless boss, Travesty, you must gather three keys from the Black Order Ninjas in the dungeon and drop them on the table in the central room. This will result in three master keys that will take you to the peerless area. The Citadel Route Finder