Called the Barrier Gate in Chinese, the Portuguese name "Gate of Siege" says a lot more to the hundreds of years of relations between the Portuguese and Chinese. The old archway, built in 1870, marked the border between Portuguese and Chinese territory, and was the actual border crossing between Macau and China until 1994, when a new crossing by the side was created. The archway and surroundings were turned into a pretty plaza. In 2004, the entire area was again renovated, with the new Barrier Gate Frontier Post being constructed north on the archway. The archway bears the dates of significant events and the motto by Luís de Camões, "Honour your country, it cares for you".

The Portas do Cerco is an area in Nossa Senhora de Fátima, Macau, China. Located on the northern tip of the Macau Peninsula, it is known by the Barrier Gate separating Macau from mainland China. The Portuguese built the gate in 1849 to replace a crumbling wall that the Chinese erected during the Ming dynasty in 1573. The Chinese built a garrisoned wall to control the flow of people and goods. It was the site of the Passaleão incident, a clash between the Qing dynasty and the Kingdom of Portugal in 1849 over the death of Macau's governor Ferreira do Amaral. Led by Colonel Mesquita, Portugal won the small battle which led to the extension of Macau's border northwards. At the limit of said expansion, the Portas do Cerco was built with the inscription "A pátria honrai, que a pátria vos contempla" (Portuguese for "Honor your fatherland, for your fatherland looks over you") on the façade on its inner arch in 1849. The Barrier Gate served as a de facto boundary, but the precise limits of Macau's border has never been formally demarcated.

Macau, now a special administrative region of China, still has an official border with Zhuhai in mainland China a few meters behind the old barrier gate. The new Posto Fronteiriço das Portas do Cerco (Barrier Gate Border Post) was opened on 15 January 2004.