LHASA, Jan. 10 (Xinhua) -- The Potala Palace in southwest China's Tibet Autonomous Region received 1.01 million tourists in 2012, said regional authorities on Thursday.

Since July 1 last year, the administration has limited the number of daily visitors to the site to 4,000 to minimize potential damage to the ancient lumber-and-dirt structure, according to the regional department of culture.

Summer visiting hours will last from 7:30 a.m. to 6:40 p.m., compared with 9 a.m. to 4:40 p.m. in the slack season.

Since 2002, China's government has invested over two hundred million yuan (about 32.12 million U.S. dollars) on maintaining the Potala Palace.

The structure is perched on craggy hills in the heart of Tibet's capital of Lhasa. It was first built by Tibetan King Songtsa Gambo in the seventh century and was expanded during the 17th century by the Dalai Lama.

It was inscribed on the UNESCO's list of world cultural heritage sites in 1994.