Sixty years later and the Frontier Closed Area has long since passed its useful life , leaving behind a natural habitat largely untouched by humans and some of the most valuable undeveloped real estate in the world . Hong Kong 's border with China includes a 26sq km land zone , the Frontier Closed Area . This is where most of the people who live in Hong Kong are allowed to go and work but not travel freely between mainland China and Macau or Taiwan. 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 . This is where most of the people who live in Hong Kong are allowed to go and work but not travel freely between mainland China and Macau or Taiwan. 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 .