Beijing, Beijing Shi (AFP) July 13, 2013Boasting its own artificial sun and a floor area three times that of the Pentagon, the "world's largest building" has opened in southwest China to mixed reviews from its first visitors. The towering 100-metre (330-foot) high New Century Global Centre, which is said to to be big enough to hold 20 Sydney Opera Houses, recently opened its doors Chengdu. The complex, which Chinese officials Reported by Terra Daily 56 minutes ago.