Introduction to Sea Measurement Building: Sea Measurement Building is a library built after Tianyi Pavilion in Ningbo. It means that learning is as deep as the sea and there is no end to learning. It is one of the four major private libraries in China in the late Qing Dynasty and the oldest existing library in my country. A good personal library. The fish pond is made of rectangular granite and is rectangular in shape, surrounded by inlaid iron railings. The water in the pond is connected to the water outside the house. The fish pond is the largest in Yangzhou.