Longdong is located at the eastern end of Longdong Gangzui, "half inferior to the sea", with a height of 14 meters, a width of 10 meters, and a depth of about 60 meters. According to the "Xiangshan County Annals" of the Republic of China, "Saw Gate Cave is located in the middle of the mountain and rock half walls, about three zhang wide. It is as round as a rule, with two caves and stalagmites and pillars." When the tide reached the bottom of the cave, the sound shook like thunder. In Song Baoqing's "Four Ming Annals", it is recorded that "the Five Dragons of the world gathered here.". In the cave, there are rocky formations, milk formations, and colorful pendants. Below, there are five colored stones that are extremely bright and lovely. They stand four or five zhang tall, with a cold and imposing aura that cannot be penetrated deeply. There is a poem from the ancients that goes: "The heavens call the three gates perilous, the cliffs seem to stretch like saws, the tides spit out and swallow each other, the dragons swim and perform, with the fragrance of dragon's saliva on them, and they can rest on the clouds and ladders.".