Longevity Hill, 58.59 meters high, is an offshoot of the Yan Mountain range. Legend says that an old man found a stone jar while chiseling at the hill rocks. The hill was therefore named Jar Hill and the lake before it, Jar Hill Lake. Also named West Lake, in time it became known as Kunming Lake. In 1494 during the reign of Emperor Hongzhi of the Ming Dynasty, the emperor’s wet nurse, Madam Luo, built a temple at the foot of the mountain, which she named the Temple of Serenity. In 1750 Emperor Qianlong’s had the Temple of Immense Gratitude and Longevity built on the site of the ruined Temple of Serenity to celebrate the 60^th birthday of his mother. The following year, the hill was renamed Longevity Hill. As the development of the Summer Palace grounds continued, soil quarried to enlarge Kunming Lake was piled up on the hill to balance its east and west slopes in terms of shape and size. This restyled hill became the mainstay of the garden. The majority of the structures built on the hillside during Emperor Qianlong’s reign (1736-1795) were burned down by the Anglo-French Allied Forces in 1860. Most of the existing buildings were rebuilt during Emperor Guangxu’s reign (1875-1908). The Tower of Buddhist Incense is a three-storey octagonal building with four-layered eaves built in front of the hill. An axis running uphill links all the structures together, starting from the archway at the foot of the hill, and going up through Gate of Dispelling Clouds, Second Palace Gate, Hall of Dispelling Clouds, Hall of Moral Glory, and Tower of the Fragrance of the Buddha, and ending on the hilltop at the Sea of Wisdom Temple. On the east hillside are the Revolving Archives, Longevity Hill and Kunming Lake Monument. Standing on the west hillside are the Pavilion of Five Locations and the Baoyun Bronze Pavilion. The buildings behind the hill include the “Four Great Regions,” a splendid Tibetan Buddhist structure, and the colorful Glazed Tile Pagoda of Many Treasures that stands amidst the trees of the hill. There is also a variety of traditional structures such as Hall of Utmost Blessing, Pavilion of Multi-layered Greenery, Painting the Autumn Pavilion, and Strolling in the Picture Scroll, etc., making Longevity Hill a concentrated illustration of classical Chinese garden architecture.