Boundaries of Hong Kong in the context of "Border barrier"

The People's Republic of China (PRC) shares land borders with 14 countries (tied with Russia for the most in the world): North Korea, Russia, Mongolia, Kazakhstan, Kyrgyzstan, Tajikistan, Afghanistan, Pakistan, India, Nepal, Bhutan, Myanmar, Laos, and Vietnam, and with two Special administrative regions of China, Hong Kong and Macao. The land borders, counterclockwise from northeast to southwest, are the China–North Korea border, the eastern segment of the China–Russia border, the China–Mongolia border, the western segment of the China–Russia border, the China–Kazakhstan border, the China–Kyrgyzstan border, the China–Tajikistan border, the China–Afghanistan border, the China–Pakistan border, the western segment of the China–India border (the most contested of the Sino-Indian border dispute), the China–Nepal border, the central segment of the China–India border (Sikkim), the China–Bhutan border, the eastern segment of the China–India border, the China–Myanmar border, the China–Laos border, the China–Vietnam border, a 3-kilometre (1.9 mi) internal border with Macau, a Portuguese territory until 1999, and a 30-kilometre (19 mi) internal border with the special administrative region of Hong Kong, which was a British dependency before 1997.

To the west, China has maritime borders with North Korea, Japan and contested limits with Taiwan and other countries in the South China Sea, among other territorial disputes.

The Frontier Closed Area (Chinese: 邊境禁區) is a regulated border zone in Hong Kong that extends inwards from the border with mainland China. It was established by the Frontier Closed Area Order, 1951, and 1984.

Established to prevent illegal migrants and other illegal activities from mainland China and elsewhere by land and sea, the closed area is fenced along its perimeter to serve as a buffer between the closed border and the rest of the territory patrolled and controlled by Hong Kong Police Force and its Marine Region and the Immigration Department at land and sea. Developments are tightly controlled within the area, leading to less construction and causing most of the area to become a natural habitat for animals and plants.