古昌是伊朗的城市，位于该国东北部，由礼萨呼罗珊省负责管辖，距离首府马什哈德125公里，毗邻与土库曼斯坦斯坦接壤的边境，海拔高度1,317米，2006年人口96,953。

Quchan (Persian:قوچان‎‎ Qučān  pronounced [quˈtʃɑːn, ɢoˈtʃɒːn]; also Romanized as Qūchān and Quçan; also known as Gochan) is a city in and capital of Quchan County, in Razavi Khorasan Province, Iran. It is located due south of the border city of Ashgabat. At the 2006 census, its population was 96,953, in 25,066 families.