Zhangzhou Er-Yi Building

　　Located in Dadi Village, Xiandu Town, Hua'an County, it is an outstanding representative of ancient circular earthen residential buildings in China, renowned as the "King of Tulou" and the "Treasure of the Nation." It is widely celebrated for its grand scale, scientific design, rational layout, and well-preserved condition, and is a National Key Cultural Relics Protection Unit. The plaque of "Er-Yi Building" has been included in the book "Famous Plaques of China."

　　The Er-Yi Building is a circular earthen structure that combines unit-style and corridor-style designs. Constructed in the 35th year of the Qianlong reign during the Qing Dynasty (1770 AD), the circular building has a diameter of 73.4 meters, with base walls 2.53 meters thick and an overall height of 16 meters. The entire building is divided into twelve units, comprising a total of 192 rooms. Its structural functions are clearly divided: the outer ring has four floors and serves as living quarters and ancestral halls, while the inner ring consists of single-story rooms for cooking and dining. Each unit has its own courtyard and stairway, forming an independent system. The fourth-floor walls are 80 cm thick, with a one-meter-wide hidden corridor connecting all twelve units, balancing privacy and cohesion. The tulou features comprehensive defensive elements: the main gate and two smaller doors are equipped with sand and water drainage holes to prevent fire attacks. Windows on the fourth floor serve as scenic outlooks in peacetime and as gunports in wartime, with built-in lamp fixtures and roof-access mechanisms. The ground floor includes hidden passages leading outside, and each unit has communication shafts for internal and external contact. Vertical shafts run from the first to the fourth floor in each unit, used for roof maintenance and emergency access. Two wells within the building provide ample drinking water for residents. The first-floor hall and fourth-floor ancestral hall feature hanging beam and pillar structures, with exquisitely carved brackets, vibrant paintings, and a magnificent aesthetic, showcasing high artistic value.

　　The Er-Yi Building is situated in the center of Dadi Village. Constructed in 1740 (5th year of the Qianlong reign), it housed 39 households and 196 residents as of 2005. This double-ring circular tulou faces northwest and covers an area of 9,300 square meters. The outer ring has four floors, while the inner ring is single-story. The outer diameter is 73.4 meters. The building is divided into 16 units, totaling 224 rooms. Four units serve as shared entrances, stairways, and halls, while the remaining 12 units are residential, each with its own staircase—representing the unit-style tulou of the Hoklo people, one of Fujian's two major ethnic groups (the other being the Hakka). The base of the outer ring walls features 12 zigzag sound-transmitting holes for communication. The top floor’s outer wall is thinned to include a 1-meter-wide hidden corridor, addressing the isolation issue in unit-style tulous during defense. The corridor connects to each unit’s ancestral hall, with 56 observation and shooting windows and 23 gunports, exemplifying the perfect integration of ancient strategic defense and living space. The 2.53-meter-thick outer walls consist of stone foundations and rammed earth, tapering upward. One main gate and two side gates are framed with granite. The inner courtyard serves as a communal space, featuring two public wells. The outer walls have no windows on the first three floors, only small openings on the fourth (see figures 7.a-1: 96, 97, 98; photos 7.a-2: 88, 89, 90).

　　Each unit enters from the central courtyard, with a private small courtyard inside for added privacy. The transition from the outer tulou space to the inner courtyard and then to individual unit courtyards caters to varying needs of communal living. The interior layout is also distinctive: entering a unit leads to the inner-ring entrance hall, flanked by kitchens and storage rooms. Corridors connect the inner and outer rings, enclosing the unit courtyard, with latticed wooden partitions separating them. The outer-ring interior differs from inner-corridor tulous—the ground floor is a living room, not a kitchen or dining area, with bedrooms on the second and third floors. The fourth-floor center hosts a spacious ancestral hall, individually managed by households, flanked by grain storage rooms.

　　Structurally, the Er-Yi Building is unique. The outer ring’s peripheral walls are earthen up to the top, as are the load-bearing inner walls extending to the third floor. Units are entirely separated by load-bearing earthen walls, with vertical walls on the first to third floors also load-bearing.

　　More uniquely, the second and third floors feature narrow wooden overhangs extending from the inner-ring walls, creating additional eaves for drying clothes.

　　The architectural decorations of the Er-Yi Building are balanced in complexity. The central axis culminates in the ancestral hall opposite the main gate, with carved and painted beams. The gate is flanked by a pair of blue-stone drum-shaped pedestals engraved with auspicious motifs like ruyi locks and dragons playing with pearls. The top-floor halls housing spirit tablets are adorned with intricate carvings and paintings. The first-floor verandas before small courtyards are another decorative highlight, with 12 unique wooden carvings above unit entrances. The tulou houses 593 square meters of murals (226 pieces), 99 square meters of paintings (228 pieces), 349 wood carvings, and 163 couplets. Themes include landscapes, flowers, birds, and figures, brimming with folk artistry (see photos 7.a-2: 91, 92, 93, 94).

　　The building’s cultural richness is reflected in its inscriptions, such as: "Inheriting virtue, prospering the land; the King of Tulou thrives in beauty" and "A harmonious home, blessed by auspicious mountains and waters." Dozens of artworks highlight the owners’ emphasis on education, like "Poetry and books nurture virtue; scholars and saints inspire." Combined paintings and couplets include "Pondering peach blossoms, wielding the spirit of landscapes" and "Filial piety and rituals, timeless literature." On the third-floor lintel of ten units, a Western semi-nude female figure is painted (photo 7.a-2: 93). Walls and ceilings in units 3, 6, and 10 display clippings from the 1931 New York Times and 1932 New York Evening Post, witnessing Sino-Western cultural exchange.