These are Huuan Tulou, which forms a part of “Fujian Tulou”.
Fujian Tulou is a type of Chinese rural huge dwellings of the Hakka people,etc.
A tulou is usually a large, enclosed and fortified earth building, with very thick load-bearing rammed earth walls and housing scores of families.
Branches, strips of wood and bamboo chips are often laid in the wall as additional reinforcement.
Many families still live there today.
Fujian Tulou (Huuan), Fujian, China