Four hills of Kowloon

The Four Hills of Kowloon () are four hills that were historically the site of granite quarries in Kwun Tong District, New Kowloon, Hong Kong.
History.
At the end of the 18th century, Hakka settled into the Cha Kwo Ling area, and quarrying became their main occupation. By that time, the villages of Cha Kwo Ling, Ngau Tau Kok, Sai Tso Wan and Lei Yue Mun were collectively called "Si Shan" (, "Four Hills"). According to a missionary who visited the area in 1844, tens of quarries were in operation along the 2 miles stretch in eastern Kowloon. In the early 20th century, the were said to be more than 10 quarries in the Ngau Tau Kok section of the "Four Hills" alone, each employing 10 to 20 people, all Hakka with origins in the East River area of northeastern Guangdong.
The Qing government appointed a headman for each "hill", in charge of ruling the area and collecting tax. The four headmen were collectively referred to as the "Si Shan Tau Yan" (, "Headmen of Four Hills"). The four villages also formed the "Si Shan Kung So" (, "Communal Hall of Four Hills"), managing the quarrying business. The headmen system ended before World War II.
The granite blocks extracted from the Four Hills were exported via sailboat, and several piers were built along the coast. The one at Sai Tso Wan was the biggest. Today, only parts of the Lei Yue Mun pier remain.
Conservation.
The Old Quarry Site Structures at Lei Yue Mun (Kowloon) have been listed as Grade III historic buildings.