On this day, 49 years ago, on June 26, 1976 (May 29, 1976 in the lunar calendar), the Sien Tower in Canada was open to the public. Photo: Sien Tower opened to the public On June 26, 1976, the Canadian National Television Tower, Sien Tower located in Toronto, was opened to the public. The tower was 553.33 meters high and had a beautiful shape. It was the tallest free-standing building in the world at that time. The Tower is a landmark building in the city of Toronto, visited by more than 2 million people every year. It is a must-visit attraction for tourists to Toronto. The Canadian National Television Tower was built in 1973 by the Canadian National Railway to showcase Canada's strong industry. Initially designed as an antenna to transmit radio and television signals, there is a microwave receiver at an altitude of 305 meters for transmitting warning signals. The broadcast antenna is located at the top of the tower. The TV tower is built with a 447-meter-high metal staircase with 1,776 levels, making it the highest metal staircase in the world. These ladders are used for emergency purposes and for hosting special events. In 1995, the Canadian National Television Tower was listed as the Seven Wonders of the Modern World by the American Society of Civil Engineers. He is also a member of the World Federation of Great Towers. The following year, Guinness World Records changed the classification of the Canadian National Television Tower to "the world's tallest building"(now the Burj Khalifa) and "the world's tallest self-contained structure."