Introduction to Sizuo: Sizuotang, also known as Wenjia Datang, is about 420 meters long and 45 meters wide. A square non-porous wood of more than 10 meters was unearthed in 1953. In 1965, a piece of guangguan wood was discovered, which was 2.22 meters long. Meters. It is calculated that such a large wooden anchor can lift an iron anchor of 500 kilograms. In 1974, a large copper anchor was dug out, 2.65 meters long. The anchor has four claws, each claw has a net length of 0.85 meters, and is curved. The anchor rod is made of cast copper and welded. According to historical records, there is a ship in this pond with a square head and square stern, several masts in the middle, and a balcony, so it needs to be excavated by archaeologists.