Taq wa San or Taq-e Bostan(Kurdish: تاق وه سان, "arch of Stone"),(Persian: طاق بستان, "arch of Bostan") is a site with a series of large rock relief from the era of Sassanid Empire of Persia, the Iranian dynasty which ruled western Asia from 226 to 650 AD. This example of Sassanid art is located 5 km from the city center of Kermanshah in western Iran. It is located in the heart of the Zagros mountains, where it has endured almost 1,700 years of wind and rain. Originally, several sources were visible next to and below the reliefs and arches, some of which are now covered. Sources next to the reliefs still feed a large basin in front of the rock. The site has been turned into an archaeological park and a series of late Sasanian and Islamic column capitals have been brought together (some found at Taq-i Bustan, others at Bisitun and Kermanshah).
The carvings, some of the finest and best-preserved examples of Persian sculpture under the Sassanids, include representations of the investitures of Ardashir II (379–383) and Shapur III (383–388). Like other Sassanid symbols, Taq-e Bostan and its relief patterns accentuate power, religious tendencies, glory, honor, the vastness of the court, game and fighting spirit, festivity, joy, and rejoicing.
Sassanid kings chose a beautiful setting for their rock reliefs along an historic Silk Road caravan route waypoint and campground. The reliefs are adjacent a sacred springs that empty into a large reflecting pool at the base of a mountain cliff.
Taq-e Bostan and its rock relief are one of the 30 surviving Sassanid relics of the Zagros mountains. According to Arthur Pope, the founder of Iranian art and archeology Institute in the USA, "art was characteristic of the Iranian people and the gift which they endowed the world with."