Complex sentence: The Jiyaguyan fort guards the western entrance to China, located in Jiayuguan pass at the narrowest point of the Hexi Corridor, some southwest of the city of Jiayuguan.
Split into simpler sentences: The Jiyaguyan fort guards the western entrance to China. It's located in Jiayuguan pass at the narrowest point of the Hexi Corridor, some southwest of the city of Jiayuguan.