'Fujian earthen buildings') are Chinese rural dwellings[1] unique to the Hakka in the mountainous areas in southeastern Fujian, China.

Smaller interior buildings are often enclosed by these huge peripheral walls which can contain halls, storehouses, wells and living areas, the whole structure resembling a small fortified city.

[3] Tulous usually have only one main gate, guarded by 4–5-inch-thick (100–130 mm) wooden doors reinforced with an outer shell of iron plate.

Instead, it is preferable to use the definition actually used in Fujian: a tulou is a large building, constructed with load-bearing rammed earth walls, and used as a residence by a community (a group of families).

Western influence is evident in the Greek style columns of the ancestral hall, and in the wrought iron railing of the second level corridor.

It is massive round tulou with four concentric rings surrounding an ancestral hall at the center, the outer ring is 62.6 meters in diameter and four stories tall, 288 rooms, with 72 rooms on each level, circular corridor on 2nd to 4th floor, with four sets of staircases at cardinal points connecting ground to top floors.

Tianluokeng Tulou cluster (田螺坑土楼群) is tulou quintet cluster located at Fujian province, Zhangzhou City, Nanjing County, Shuyang Township, Tian Luo Keng Village (literally "Snail Pit" Village) in southern China, about four hours drive by motor coach or taxi from Xiamen, through winding and bumpy narrow mountain roads.

But in spite of this apparent infirmity, this tall tulou withstood 700 years of natural elements and social turmoil.

[14][15] One of the tulous in this large cluster, the Yanxiang Lou (衍香楼), a round tulou in Xinnan Village (新南村, 24°36′22″N 116°58′30″E / 24.60611°N 116.97500°E / 24.60611; 116.97500) figures on the World Heritage List as Site 1113-004.

The layout of Fujian tulou followed the Chinese dwelling tradition of "closed outside, open inside" concept:[citation needed] an enclosure wall with living quarters around the peripheral and a common courtyard at the center.

A small building at the center with an open front served as an ancestral hall for ancestry worshipping, festivals, meetings, weddings, funerals and other ceremonial functions.

The ground floor plan includes shapes such as circles, semicircles, ovals, squares, rectangles, and irregular pentagons.

The foundation of tulou buildings were built with paved stones on top of compacted earth ground, in two to three tiers.

In most cases, the weight bearing outer wall of tulou consists of two sections, the lower section is built from cut stone blocks or river cobbles held together with a lime, sand and clay mixture to a height of about one or two meters, depending upon the regional flood water level.

The rooftops were covered with baked clay tiles, arranged radially;λ insertion technique was used at regular intervals to compensate for larger circumference at the outside.

Circular corridors from 2nd to uppermost level were made of wood boards laid on horizontal wooden beams with one end inserted into the earth wall.

Most tulous have in built water pipes to offer protection to the upper wooden floors against fire (either accidental or as a result of attack).

However, Huang Hanmin discovered that the Shunyu Lou (顺裕楼) in Nanjing county is even larger, with a diameter of 74.1 meters.

[16] Cuilin Lou (翠林楼) in the Nankeng township of Nanjing county is the smallest tulou, with a diameter of 14 meters.

All rooms were built the same size with the same grade of material, same exterior decoration, same style of windows and doors, and there was no "penthouse" for "higher echelons"; a small family owned a vertical set from ground floor to "penthouse" floor, while a larger family would own two or three vertical sets.

Besides the building itself, many facilities such as water wells, ceremonial hall, bathrooms, wash rooms, and weaponry were shared property.

The family houses face the central ancestral hall, symbolizing worship of ancestry and clan solidarity.

With the development of new housing with modern facilities in rural China, many tulou residents have moved out of the structures or relocated to larger towns or cities for better jobs.

The lower one- to two-meter section of the outer wall was sometimes built with granite blocks or large river cobbles.

The main gate door was barred with several horizontal and vertical strong wood posts inserted into holes in the granite.

Fujian Tulou residents used firearms for active defense, shooting at enemies from gun ports at the top level of the building.

Some Fujian tulou are constructed with a circular corridor along the inside wall to facilitate the movement of armed men and ammunition.

[20] In April 1957, the article Dwellings of the Hakka in Yongding County of Fujian Province (福建永定客家住宅) by Zhang Buqian (张步骞), Zhu Mingquan (朱鸣泉) and Hu Zhanlie (胡占烈) published in the Journal of Nanjing Institute of Technology.

Since the opening of the high-speed Longyan–Xiamen Railway (June 2012), travelers are able to reach Longyan from Xiamen in 45 minutes; there is direct service from Fuzhou and Shanghai as well.

To celebrate the tulou heritage of the county, the architects designed the new station building at Nanjing in the shape of three round tulous.