From Halopedia, the Halo wiki
Bars, Alföld, Reach
Esztergom, alternatively spelled Ezhtergom, was a major city located in Bars, Alföld on planet Reach. One of Reach's largest cities along with Manassas and Quezon, Esztergom also housed a spaceport.
Esztergom is a city in northern Hungary.
Esztergom's Spaceport Stamp