in various books related to kushan empire. His greatest contribution to Buddhist architecture was the Kanishka stupa at Purushapura, modern day Peshawar. Archaeologists who rediscovered the base of it in 1908–1909 estimated that this stupa had a diameter of 286 feet (87 metres). Reports of Chinese pilgrims such as Xuanzang indicate that its height was 600 to 700 (Chinese) "feet" (= roughly 180–210 metres or 591–689 ft.) and it was covered with jewels. Kanishka is said to have been particularly close to the Buddhist scholar Ashvaghosha, who became his religious advisor in his later years. Buddhist coinage The Buddhist coins of Kanishka are comparatively rare (well under one percent of all known coins of Kanishka). Several show Kanishka on the obverse and the Buddha standing on the reverse. A few also show the Shakyamuni Buddha and Maitreya. Like all coins of Kanishka, the design is rather rough and proportions tend to be imprecise; the image of the Buddha is often slightly overdone, with oversize ears and feet spread apart in the same fashion as the Kushan king. Three types of Kanishka's Buddhist coins are known: Standing Buddha Only six Kushan coins of the Buddha are known in gold (the sixth one is the centerpiece of an ancient piece of jewellery, consisting of a Kanishka Buddha coin decorated with a ring of heart-shaped ruby stones). All these coins were minted in gold under Kanishka I, and are in two different denominations: a dinar of about 8 gm, roughly similar to a Roman aureus, and a quarter dinar of about 2 gm. (about the size of an obol). The Buddha is represented wearing the monastic robe, the antaravasaka, the uttarasanga, and the overcoat sanghati. The ears are extremely large and long, a symbolic exaggeration possibly rendered necessary by the small size of the coins, but otherwise visible in some later Gandharan statues of the Buddha typically dated to the 3rd–4th century CE (illustration, left). He has an abundant topknot covering the usnisha, often highly stylised in a curly or often globular manner, also visible on later Buddha statues of Gandhara. In general, the representation of the Buddha on these coins is already highly symbolic, and quite distinct from the more naturalistic and Hellenistic images seen in early Gandhara sculptures. On several designs a mustache is apparent. The palm of his right hand bears the Chakra mark, and his brow bear the urna.