Hong Kong 's border with China has a 26sq km land zone , the Frontier Closed Area . The Cold War - era zone has been largely untouched by humans since the 1950s . The Hong Kong government has recently opened up a portion of the closed area to the public . Conservationists fear developers could encroach on the zone which is home to migratory birds .
Hong Kong 's border with China includes a 26sq km land zone , the Frontier Closed Area . The Cold War-era zone has been largely untouched by humans since the 1950s . The Hong Kong government has recently opened up a portion of the closed area to the public . Conservationists fear developers could encroach on the zone which is home to migratory birds .