The Humen, also Bocca Tigris or Bogue, is a narrow strait in the Pearl River Delta that separates Shiziyang in the north and Lingdingyang in the south near Humen Town in China's Guangdong Province. It is the site of the Pearl River's discharge into the South China Sea. It contains the Port of Humen at Humen Town. The strait is formed by the islands of Chuenpi and Anunghoy on the eastern side, and Taikoktow on the western side. Since 1997, the strait has been traversed by the Humen Pearl River Bridge. Bocca Tigris was the entry to China's only trading city, Canton.

The Pearl River Delta Metropolitan Region is the low-lying area surrounding the Pearl River estuary, where the Pearl River flows into the South China Sea. Referred to as the Guangdong–Hong Kong–Macao Greater Bay Area in official documents, the region is one of the most densely populated and urbanized regions in the world, and is considered a megacity by numerous scholars. It is currently the wealthiest region in Southern China and one of the wealthiest regions in China along with the Yangtze River Delta in Eastern China and Jingjinji in Northern China. Most of the region is part of the Pearl River Delta Economic Zone, which is a special economic zone of China.