Collapse of 'Moon Gate' raises questions of best ways to safeguard icon

The recent collapse of the Great Wall's "Moon Gate" - a well-known landmark in Guangwu, Shanxi province - has put protection of the wall into the limelight a second time in a few weeks.

The gate, which was already suffering decay, was part of an old watchtower. It apparently collapsed on Monday night. Local authorities have yet to make an official statement.