Chengqi Building has four floors high, three doors. The first floor is the kitchen, the second floor is the granary, the third and fourth floors are the bedrooms, only the third and fourth floors have windows. Chengqi Building has five characteristics: 1. The longest history, built in 1628, 2. The most land, 6,000 square meters, 70 meters in diameter, 3. The most living population, the most 80 households, more than 600 people, 4. Tulou is the structure of the concentric circle, 5. The architect is the most experienced. There are four rows of concentric circles in the earth building. The first row has 76 rooms, which is a place to take a bath. The second row has 36 rooms, which are a place to entertain guests, and also a place to drink tea and chat. There are two Yangjing and Yinjing. The third row of rooms is larger, with 20 rooms, for reading rooms, with paper money bricks in front of the door, and pen flowers. The fourth row is the Guanyin Hall, also known as the party hall, which is a place for important business meetings. All rooms in the Tulou are fan-shaped. Each floor of the earth building is 20 cm thicker than the upper floor. When building the earth building, the wall is mixed with bark and branches to increase the strength of the building.