About 15 million tourists have visited the Yungang Grottoes, a 1,500-year-old World Heritage site in northern China's Shanxi Province, over the past five decades, an expert said Tuesday.

The tourists included nearly 20 distinguished foreign guests like the French president, the British prime minister, the Netherlands queen and the Thai princess, according to Li Lifen, vice president with the Yungang Grottoes Research Institute.

Li revealed the information on the sideline of a five-day international seminar that opened Tuesday at Yungang to discuss the protection and study of grottoes.

Over 300 experts from dozens of countries and regions participated in the seminar, which coincides with the institute's 50th anniversary.

The Yungang Grottoes were opened to public in 1977 when a three-year repair project was completed. The number of visitors remained stable at about 200,000 annually in the two decades during 1980s and 1990s and reached a peak in 2004 when 520,000 tourists flocked to the site.

The grottoes, carved on a one-km-long cliff, boast about 51,000Buddha statues, the biggest of which is 17 meters high and the smallest of which is only several centimeters.

The Chinese government launched a series of projects to protect the grottoes, helping the grottoes to survive water erosion and rescuing them from collapsing over the past 50 years.

Another anti-infiltration and drainage project is expected to be launched within the year to eliminate the water-erosion problem facing the grottoes, experts say.

(Xinhua News Agency July 27, 2005)