The vast ceremonial chamber in the First City on Qo'noS where the Klingon High Council sits under its Chancellor to hear challenges, pass judgement and decide the affairs of the Empire.
The Great Hall is first seen in the Next Generation episode Sins of the Father. Worf comes before the council there to contest the charge that his father Mogh betrayed Khitomer, and ends by accepting discommendation, the councillors turning their backs on him one by one, in order to protect the Empire from civil war.
The chamber returns in the two parts of Redemption. Gowron is installed as Chancellor there, Lursa and B'Etor present Toral as a rival claimant, and Worf's family honour is restored. Picard attends as Arbiter of Succession.
The same setting recurs in later series, notably in the Deep Space Nine episode The House of Quark, when Quark argues a case of Klingon inheritance before Gowron with a ledger of accounts.