Old Cleveland
From Halopedia, the Halo wiki
Old Cleveland is the old 21st century part of Cleveland in the year 2552. It was the place where the Covenant gathered the citizens of the city in order to find out where the Key of Osanalan was located after the Battle of Cleveland.
Once the Ark was activated the Covenant forces occupying Old Cleveland were sent to Africa to travel through the Ark. With the rest of the Covenant Fleet.