High Council Chamber
From Halopedia, the Halo wiki
The Council Chamber is the enormous hall within High Charity that the Covenant High Council meets to discuss policy, discipline among ranks, and military plans. The walls are lined with large bleacher-like seats. The Prophet and Elite Councillors sit on opposite sides of the chamber. In the center of the chamber is a podium from which an alien may stand to speak or be judged. On one end of the chamber is the entrance to the Sanctum of the Hierarchs, and from this end the three High Prophets sit and address the council. On the other end is an entrance to the city of High Charity.
The council chamber is the first room that the Master Chief comes across in High Charity, after being teleported there by the flood creature Gravemind. He then aims to kill the prohets and take Instalation 05's index, to stop the Covenant activating the ring. However, the Prophets escape through a lift at the end of the hall and the Chief has to kill Brute Honor Guards to advance to the Prophets.
Following the Flood invasion of the station, the Council Chamber was taken over by the Gravemind. It seems that Gravemind uses the Council Chamber as a sort of "Throne room." Cortana was also in the council chamber in the end of Halo 2. At the end of the credits for Halo 2 there is a cut scene of the Gravemind asking for more answers about the Halos.
