Misty Rain Pavilion, also known as Yan Yu Tower, named after Tang Dynasty poet Du Mu's verse "In the mist and rain of the southern dynasties' four hundred eighty temples, how many towers and pavilions," was originally built during the Later Jin of the Five Dynasties period (936-947 AD). Initially located by the shore of South Lake, it was moved to a small island in the lake in the twenty-eighth year of the Ming Jiajing era (1549 AD), the second year after the island was formed by piling up silt. Since then, it has become the core and symbol of the ancient architectural complex of South Lake. Over the past four hundred years, Yan Yu Tower has been built and rebuilt multiple times, enduring many vicissitudes. The last major renovation before liberation was in 1918, undertaken by Zhang Changqing, the magistrate of Jiaxing. The main tower of Yan Yu Tower is approximately 20 meters high, with two stories and a building area of 640 square meters. It features double eaves, painted beams, red pillars, and bright windows, creating an impressive sight. A plaque inscribed with "Yan Yu Tower" by Dong Biwu hangs from the front eaves. The couplet in the main hall below, also written by Dong Biwu, reads: "In the mist and rain of this tower, the revolution was sparked; here, sparks once flew. In the wind and clouds of the world, awakening with the spring, the sound of thunder is heard everywhere." Climbing Yan Yu Tower to view the scenery of South Lake offers a unique charm. In summer, leaning against the railing, one sees endless green lotus leaves across the lake; in spring, with light rain drizzling, the lake is shrouded in mist and rain, presenting a scene enveloped in fog.