Beigan North Sea Tunnel Introduction
The North Sea Cave, a man-made marvel, was began in 1968 as part of the "North Sea Project", which was initiated for strategic needs in the Matsu region, where numerous "underground docks" were excavated for the use of guerilla speedboats. Today, after being decommissioned by the military, it has become a unique "wartime landscape" in the Matsu region. Visiting the North Sea Cave is considered a must-do when coming to Matsu. The North Sea Cave is located along the Tiebang coastline and features a waterway that penetrates deep into the mountain, intersecting in a "well" shape. The waterway is 18 meters high, 10 meters wide, and 640 meters long. During high tide, the water level can reach 8 meters, while at low tide it drops to 4 meters. The walking path is 700 meters long, and it takes about 30 minutes to complete a loop, but visitors must time their visit according to the tides, as entry is only allowed during low tide. This underground cave can accommodate over a hundred landing craft and was once considered a high-difficulty engineering project. It involved the mobilization of two divisions, three infantry battalions, one engineering battalion, and a mixed unit of dump trucks working around the clock in three shifts, culminating in the completion after 820 workdays. Given the limited construction equipment at the time, the cave was carved from granite walls primarily by hand using picks and axes, leading to several casualties among the servicemen. The formidable engineering challenge and grand scale of construction are truly commendable. In the past, during a time of military tension, the North Sea Cave attempted to function as an underground dock; today, as visitors walk into the vast cave, they are met with majestic rock walls and floating dim reflections that evoke awe. Note: The cave is open for visitors, but access requires synchronization with the tidal changes during the day, so visitors are advised to pay attention to the tide times! For night excursions, it is an excellent spot to witness "blue tears." In recent years, due to the discovery of "blue tears," and the low light pollution at the entrance of the cave, the North Sea Cave has become one of the hot spots for viewing blue tears on Mazu's Nangan Island. Visitors can take a small boat and gently row into the cave to seek out the faint glowing phenomena, making for a worthwhile experience. Note: The "blue tears" is a natural phenomenon, and the conditions for its appearance are unpredictable. Please refrain from using flash photography, and for safety reasons, passengers are prohibited from standing up or changing seats while the boat is in motion.
