Map of Western China, (not really clear) where East meets West on the ancient silk road. Here refugees, mostly religious refugees flee Central Asia and the far borders of the Byzantine empire. Manichaens and Zorastrians leave Europe to settle here. Later Chinese monks goes to India to learn about Buddhism and return with a plethora of ideas which were translated into sutras, banners and frescoes. Here in the Gobi desert of Western China, thousands of caves were made into temples and the German explorers helped themselves to whatever they could unload from the caves and load them onto camel trains to bring back to Germany. Most of these were destroyed by Allied bombings during the second world war. What remains is in this museum in Berlin. These were from mostly the Bezilik caves in Western China. The English explorer, Sir Aurel Stein, went to another area, the Dunhuang caves near Turpan. He didn't have the technology to remove panels of frescoes that the Germans had. He removed thousands of sutras, he was followed by the French explorer, Paul Pelliot and later, Count Otani from Japan and even the Americans.' Today these treasures are found in Germany, England, Japan, Paris and the US. I think the museum in New Delhi, India has some also. I went to Dunhuang a few years ago, there are still hundreds of cave temples left with incredible Buddhist frescoes.
It was a huge effort getting to Dahlem, took 2 changes of underground train and an hour to get there. I went on a Monday but it was closed. I had to return the next morning. It was well worth it.