Located at 25 km (16 mi) southeast of the center of Dunhuang, the Mogao Caves, a system of nearly 500 temple grottoes, preserves an unparalleled treasure trove of Buddhist art, featuring exquisite murals and thousands of painted sculptures created over a span of a thousand years. The first caves were dug out in 366 CE and caves continued to be built at the site until the 14th century. Photography is forbidden inside the caves.