From the Rossio Square, you can see the sea of Lisbon. There is a particularly famous square commercial square, which is one of the most important squares in Lisbon. It is adjacent to the Tejo River, also known as the Palace Square. The Rivera Palace was once located here in the 1755 earthquake. After the earthquake, the Marquis of Pombal completely converted the square into a part of the lower town of Pombal. Commercial Plaza is known as one of the most beautiful squares in Europe, surrounded by a yellow municipal building on three sides, with the statue of Don Joseph I riding in the middle, because the horse sculpture is black and the commercial square has a nickname - - "Black Horse Square". Since the beginning of the 16th century, due to the construction of the Rivera Palace, the area has further developed port and shipbuilding facilities, the Indian House and other management between Portugal and other European countries and African, Asian and American colonies The administrative building of the trade, etc., the important institutional buildings at that time were located around the square.