Shajiao Fort guarded the lower Pearl River from a position closer to the open sea than Humen's better-known inland forts. Built in 1801, it formed part of the first line of defence at the river mouth and helps explain why this stretch of water became so important during the Opium War era.
Visit it with Weiyuan Fort and the Lin Zexu Memorial Museum for a fuller picture of Humen's military history.