According to the girls who showed me around, the Buddha was built in the 8th century in a time of great strife - the emperor’s idea was that building a vast buddha might help put an end to the famine and warfare that were affecting the country at the time. They told me that about 2 million people were involved in its construction! Although the hall around it has been destroyed by fire and rebuilt twice, the buddha is still more-or-less his original self, I think, although he’s onto (at least) his second head, because the original fell off in an earthquake. And one of his shoulders has been patched too. I suppose you have to expect a certain amount of wear and tear in 1200 years…