At the intersection of Zhanggong and Lianxi roads, the Yongjin Gate stands as a physical threshold where ancient engineering meets the flow of the Gong River. This gate, a key passage of the Ganzhou Ancient City Wall in Jiangxi Province, began as a simple rammed-earth barrier raised by the prefect Gao Yan in 349 AD. Centuries later, the military governor Lu Guangchou expanded its footprint, opening the five major gates of the city including Yongjin. Between 1056 and 1063, the prefect Kong Zonghan transformed these earthen mounds into a formidable shield of stone and kiln-fired brick to repel seasonal floods.

To secure the foundations against the relentless river currents, Song Dynasty builders poured molten iron into the stone joints, creating an unyielding anchor. They packed a dense core of rammed earth, then wrapped it in heavy masonry. If you run your hand along the four-meter-high flanking walls, you can feel the raised characters stamped into the clay. These inscribed bricks, some dating to the Xining era of 1069, record the names of the long-dead officials, administrative offices, and kiln sites responsible for their manufacture.

Yongjin Gate was a place of commerce. Merchant vessels, having survived the treacherous eighteen rapids of the Gan River, unloaded their cargoes at this bustling dock. The gate also functioned as a hydraulic valve. Beneath the masonry lies the Fushougou, a subterranean drainage network shaped like ancient seal characters, built during the Xining era (1068–1077) by the prefect Liu Yi. At the foot of the gate, a heavy metal flap gate hangs over the drainage outlet. When the city filled with rainwater, the pressure pushed this gate open, releasing runoff into the river. When the Gong River swelled, the external water pressure forced the flap gate shut, sealing the city against backflow.

Though city planners demolished the southern walls in 1958, they spared Yongjin Gate. The gate was rebuilt in 1994 to accommodate the rising waters of the Wan'an Hydropower Station. Today, it remains a public thoroughfare. Pedestrians walk through the same archway where Song merchants once stepped ashore, passing over the silent, ancient flap gates that still guard Ganzhou from the river.