TAIYUAN, Oct. 8 (Xinhua) -- A 500-year-old arch door on the Great Wall has been reduced to ruins in north China's Shanxi Province after a strong gale hit earlier this week.

The archway had been the remains of a former watchtower on the Guangwu Great Wall section built during the Ming Dynasty (1368-1662). It was called the "Moon Gate" by Great Wall aficionados due to its round shape.

"The arch door had been on the verge of collapse before the unusual wind storm devastated it Monday night," said Zhang Bingfa, a Great Wall preservationist with Shanxi Great Wall.

During the National Day holiday, which ended on Friday, many tourists and amateur photographers came to the site only to find the ruins cordoned off.

China's existing Great Wall sections mostly date from the Ming era, with the Ming wall measuring over 8,800 kilometers.

The Guangwu section of the Great Wall in Shanyin County, Shanxi stretches more than 6 km. Great Wall fans love the section because it has retained the original look of the wall.

However, much of the Guangwu Great Wall is in bad shape, said Zhang.

Preservationists said relic departments should make timely reinforcements and repairs to the section. They said if the wall is reduced to ruins, it becomes more difficult to restore it to its original appearance.