Chengqi Tulou, Traditional communal residence in Yongding County, China.

Chengqi Tulou is a circular earthen building 73 metres in diameter covering 5,376.17 square metres, with four concentric rings: an outer four-storey ring 16.4 metres high with 72 rooms per floor, a two-storey second ring with 40 rooms per floor, a single-storey third ring with 32 rooms, and a central ancestral hall, totalling 402 rooms. Its rammed-earth outer wall is 1.5 metres thick at the base and 1 metre at the top, with eaves projecting nearly 4 metres.

Chengqi Tulou was begun in the Chongzhen era of the Ming Dynasty and completed in 1709, the 48th year of the Kangxi reign of the Qing. It was built by the Jiang clan, who named it Chengqi Lou; tradition also calls it Tianzhu Lou, the tower aided by heaven. In 2001 it was listed as a Fujian provincial and then a national key cultural relic.

Chengqi Tulou was built by the Jiang clan, and its name means "inheriting and opening," while locals also call it Tianzhu Lou, the "Heaven-assisted building," from a tale of divine help during construction. About 300 people still live in its rings today, and the building appeared on the 13th stamp of China Post's 1986 Chinese dwellings series.

Chengqi Tulou stands in Gaobei village, Gaotou township, Yongding district, Longyan, Fujian. Visitors enter through the outer four-storey ring and pass inward through the two-storey second ring and the single-storey third ring to the ancestral hall at the centre. The outer wall is 1.5 m thick at its base and 1 m at the top, with eaves projecting nearly 4 m.

The walls are made from compacted earth mixed with stone and bamboo, representing an unusual building technique used in this region for centuries. These materials naturally store and release heat, keeping the building cool in summer and warm in winter, which partly explains why it has lasted so long.