The Buddhist pilgrim monk Xuanzang visited the Kullu Valley in 634 or 635 CE. He described it as a fertile region completely surrounded by mountains, about 3,000 "li" in circuit, with a capital 14 or 15 "li" in circumference. It contained a Stupa built by Mauryan Emperor Ashoka, which is said to mark the place where the Buddha preached to the local people and made conversions, Stupa was taken away by a Mughal ruler and put in Feroz shah Kotla maidan in Delhi. There were some twenty Buddhist monasteries, with about 1,000 monks, most of whom were Mahayanist. There were also some fifteen Hindu temples, and people of both faiths lived mixed together. There were meditation caves near the mountain passes inhabited by both Buddhist and Hindu practitioners. The country is said to have produced gold, silver, red copper, crystal lenses and bell-metal.