考古队在遗址中发现了关城的城门和瞭望台，推测它曾用于守卫边境。
Archaeologists discovered the gate and watchtower of the fortified pass at the site, leading them to believe that it was once used to guard the border.
Archaeologists discovered the gate and watchtower of the fortified pass at the site, leading them to believe that it was once used to guard the border.