Yanzidong is located on one side of the road 28 kilometers east of Jianshui ancient city, about 200 kilometers away from Kunming. The cave is more than 4000 meters long, and the entrance is more than 50 meters high and 30 meters wide, which is magnificent. Every spring and summer, hundreds of thousands of swifts fly from Malaysia, Indonesia and other places to nest and hatch eggs here, hence the name Swallow Cave, which is divided into upper and lower parts, a dry part and a wet part. You can enter the country by land or by boat. There are three groups of large karst landscapes in the cave, with a tourist area of more than 40,000 square meters. There are dozens of halls and hundreds of scenic spots in the whole water tunnel. Perhaps the most unforgettable thing about traveling in Yanzidong is the hundreds of thousands of swallows, who are whispering and flying up and down. The chirp and the sound of flowing water in the cave combine into a unique symphony, which is thought-provoking. Yanzi Cave is the most well-preserved karst cave group in the northwest of China, with the richest wind landscape and the largest capacity. There are various kinds of water in caves, caves in caves and stalactites hanging upside down at the top of caves, and there are dozens of independent scenic spots. It's like being in Qiongyao Wonderland, which is a veritable "rock palace and stone house". The auxiliary tourist attractions of Yanzidong include Lingque Shanzhai, well-preserved ancient street houses and century-old Ming and Qing theaters. The main scenic spot, Yanzidong, is located under the main peak of Wangjiadaliang on the north side of the middle reaches of Fushui River, 3 kilometers away from Guzhen 1.3 and about 80 meters away from the water surface. It is a limestone cave group produced by the Cambrian Paleocene crustal movement, with a history of 500 million years. The proven area is 20,000 square meters. It is called the first swallow cave in the northwest, located in the Fushui River Canyon, surrounded by Qifeng Song Qi. In front of the cave is the Black Dragon Cave, which is warm in winter and cool in summer. This is another miracle. The rocks are covered with green trees, the ancient trees are wrapped with vines, the branches are singing and dancing, and the fields are covered with flowers and plants. Swallow Cave, Changling Grand Canyon, Gangjia Ancient Village, Lion Ridge, Hump Mountain, Tiegu Town and Lingque Mountain have become a natural scenic spot with beautiful scenery and perfect ecology, covering an area of more than 20 square kilometers in Fiona Fang. There is a kind of "short-billed Jin Siyan" on Shennongjia. This kind of Jin Siyan lives in uninhabited mountainous areas. They don't leave all year round, unlike other swallows who fly south in winter. Despite the storm, rain, ice and snow, Jin Siyan is still soaring on the beautiful sea. Even in dense fog, they can rise to the height of 1000 meters, which is invisible to the naked eye. They live in the swallow cave of Yanzi Cliff in Shennongjia. The swallow cave is deep and about 20 meters high, and the cave is quite wide, which can accommodate thousands of people.