SHANGHAI, April 27 -- The basement and an annex of China's tallest building, the Shanghai Tower, have opened to the public as a trial for opening the rest of the building later this year, said local authorities on Wednesday.

The five-story annex is designed for holding conferences. It includes one hall of 2,000 square meters, and another of 1,000 square meters that can be divided into several separate rooms, as well as an open-air garden.

The basement houses an exhibition on skyscrapers.

Construction of the Shanghai Tower began in 2008 in the commercial center of Lujiazui in Pudong New Area. With 137 stories and 632 meters tall, it is the world's second-tallest building after the Burj Khalifa in Dubai. The Shanghai Tower includes offices, commercial space, a five-star hotel, exhibition and conference halls, and recreational facilities.