The Guanhai Longdike is located in the Waizizai Protection Area of Bali District, New Taipei City, on Section 1, Zhongzheng Road, 87th Lane, facing the estuary, with the Fisherman's Wharf on the right and Bali on the left. The dike is 306 meters long and is the top of the Waizai estuary, also the best spot to watch the Tamsui River and the estuary. Due to military presence nearby, entry was once prohibited, but it has been opened to the public for wave-watching, bird-watching, and sightseeing. The Bali Waizai and Tamsui Yuche Kou are on the south and north banks of the Tamsui River, overlooking each other, with the Tamsui River flowing into the Taiwan Strait. Standing on the wooden platform of the Guanhai Longdike, the excellent scenery of the sea and sky merging into one line is breathtaking. Along the dike, there are bilingual (Chinese and English) ecological plant signs explaining plants such as the mahogany and cactus. During low tide, a large variety of hermit crabs can be seen scurrying beneath the dike, allowing visitors to appreciate the natural ecology.