Tokyo Sky Tree, under construction in Tokyo, topped the 600-meter mark Tuesday, becoming the world’s highest self-standing tower nearly two years and seven months after the construction began in July 2008, the operator said. The new communications tower in Tokyo’s Sumida Ward reached 601 meters, eclipsing the 600-meter-high Canton Tower in China, Tobu Tower Sky Tree Co said. It will enter the final phase of construction to reach the 634-meter tidemark, the operator said.