William is British,but he is an expert(专家)on China's Great Wall. He married a Chinese woman and lived in Beijing. His two sons,James and Thomas,are 28 and 21 years old. They have shared their father's interest in the Great Wall since they were children.
In 2016,the brothers made some videos about the Great Wall. Some of them were shown on the BBC and some Chinese websites. Last year,they decided to take it a step further to experience the Great Wall by walking along it.
On July 15 last year,the brothers set out from Jiayu Pass in Gansu Province. They walked about 30 kilometres a day. They sometimes spent the night in hotels. Other times,they camped in the wild.
The two traveled along the main part of the Great Wall from west to east. After 131 days,they finally reached the Shanhai Pass in Hebei Province. Their journey covered more than 3,000 kilometers.
William is very proud of his sons. "The Great Wall is more complicated(复杂的)than we had thought," said the brothers. "This trip has given us a better understanding of it!"