The Barrier Gate (Portas do Cerco), which was built more than a century ago, marks the boundary between the enclave of Macau and the People's Republic of China.
The Barrier Gate fell decades ago when the Chinese reasserted their dominance over Macau.
mnli hypothesis: The Barrier Gate fell decades ago when the Chinese reasserted their dominance over Macau. premise: The Barrier Gate (Portas do Cerco), which was built more than a century ago, marks the boundary between the enclave of Macau and the People's Republic of China.