Hujing Military Observation Post is located on Xishan mountain. What you see is a small stone bunker, but beneath it lies an underground facility the Japanese military built to monitor activity on the sea. Locals call it the “ant hole.” Around 1940, the Japanese began installing coastal defenses in Hujing. The observation post was the first and was rumored to be Japanese admiral Isoroku Yamamoto’s command center, a claim that was later disproven––the “ant hole” was merely a coastal defense installation.
The post has an entry and exit portal at each end of a north-south passageway. The underground facility was constructed with reinforced concrete. It's about 42 meters long and 20 meters wide and is divided by a long, narrow passage. Housed within it are a barracks, an office, a warehouse, and a communications room. Personnel usually entered through the north portal and exited from the south portal. There’s also a small telescope platform by the south portal for monitoring military movements at sea. The post was an important Japanese military fortification.