Museums don't let tourists take photos because the flash can ruin the exhibits.
Visitors can take flashless photos, for a fee.
Flashless photography is OK for educational purposes. To view this video, you will need to install RealPlayer . On our way to Zhangye, we stopped in Dunhuang, a major site on the ancient Silk Road. These people are Idolaters and live by their agriculture. Ever since 366 A.D., desert travelers have paused here to ask for safe passage, adorning caves with Buddhist imagery and sculpture to help assure safe passage.