Rockefeller Center was named after John D. Rockefeller Jr. He leased space from Columbia University in 1928 and turned it into an opera house. He changed his mind after the stock market crashed. He then leased the space for 99 years. In 1989, Rockefeller Group fully bought out the property. The Radio City Music Hall was completed on December, 1932. It was the largest and most opulent theater in the world. The name of the theater was then changed to "Radio City". Radio City became the biggest tourist destination in the city and was declared a New York City land mark in 1978. In Rockefeller Center, there is a GE building. A GE building is an Art Deco skyscraper. It is in the center of Rockefeller Center. At the front of the Lower Plaza, through the Channel Gardens and Promenade a masterpiece was born. Paul Mansip the builder made the annual Yule tree. Everyone goes there to see the tree which is decorated for Christmas every year. On Christmas Day in 1936, an ice-skating rink was finally installed. After that day, it became a tradition to ice-skate there during the Christmas week. In Rockefeller Center, there are many creative sculptures. On of them is the Prometheus. There are so many building in Rockefeller too. It stretches 8 million square feet on 12 acres in Midtown, bounded by Fifth and Sixth Avenues. Two small parks are also part of Rockefeller Center; Garden Park and McGraw-Hill Park.