The Siyi (Seiyap or Sze Yup in Cantonese; Chinese: 四邑; pinyin: Sìyì; Jyutping: sei3 jap1; lit.

[1][2] One of the early descriptions of the land came from the American missionary, William Speer, who lived there around 1850 and observed: "Towns embowered in bamboo, a species of banyan and other trees meet the eye on every hand.

[11] Endowed with only limited arable lands, with much of the terrain either rocky or swampy, Sze Yup was the "pre-eminent sending area" of overseas Chinese.

[7] In addition to being a region of major emigration abroad, Sze Yup is a melting pot of ideas and trends brought back by overseas Chinese.

For example, many tong lau in Chekham and diaolou in Hoiping and Toishan built in the early 20th century incorporate architectural features from both China and the West.