He says it was also an important commercial hub where commodities transported along major trade routes like the Tea Horse Road were traded, and that today the area is home to a dozen ethnic groups, who live and do business in the area.
Zhang says that seeing people praying, reciting scripture, or prostrating themselves along the circumambulation path around Jokhang Temple was a striking experience. "I felt that the culture and history (of Xizang) was so vividly presented before me.
"Some things haven't changed much here as people are doing what those before them have been doing for centuries," he adds.
"They followed their routines while being watched by tourists and seemed totally oblivious to the curious looks they were getting. That aroused in me the wonderful feeling that those praying and the tourists were in two different worlds, and yet, we respected each other."
Palden Nyima and Yang Lurong contributed to this story.
Contact the writers at linqi@chinadaily.com.cn