Frontier Closed Area in the context of "Border zone"

The Boundaries of Hong Kong, officially the Boundary of the Administrative Division of the Hong Kong Special Administrative Region of the People's Republic of China (Chinese: 中華人民共和國香港特別行政區行政區域界綫), is a regulated administrative border with border control in force under the One country, two systems constitutional principle, which separates the Hong Kong Special Administrative Region from mainland China, by land border fence of 30 km (19 mi) and maritime boundary of 733 km (455 mi), enforcing a separate immigration and customs-controlled jurisdiction from mainland China.

The boundaries of Hong Kong are patrolled and controlled by the Hong Kong Police Force and its Marine Region and the Immigration Department at land and sea. The land boundary also includes a buffer zone, known as Frontier Closed Area.

Sha Tau Kok (Chinese: 沙頭角; Cantonese Yale: Sā Tàuh Gok) is a closed town in North District, Hong Kong. It is the last remaining major settlement in the Frontier Closed Area and is Hong Kong's northernmost town. Its residents are mostly descendants of Hakka farmers and Hoklo fishermen who settled the area as a consequence of the Qing dynasty's "Great Clearance" in the 17th century.

The town can be accessed via Sha Tau Kok Road and public transit beginning in Sheung Shui. However, visitors who do not possess a valid Closed Area Permit and identification are turned away at the police checkpoint guarding the entrance to the town. There are additional restrictions on access to Chung Ying Street, which separates the Hong Kong portion of Sha Tau Kok from the mainland Chinese portion in Shenzhen (Shatoujiao Subdistrict). Although the Hong Kong government now promotes tourism in the historically isolated town, Chung Ying Street remains closed off to most outsiders, including Hong Kong residents without permits.