One place that still leaves traces of the past is Pa Bo Sip Song, Phayao Province. Phayao City is a city that has a lot of natural resources to create sandstone art. In an era in the Kingdom of Phu Kam Yao with the creation of Buddhist art in various ways according to beliefs and ideals By bringing a lot of sandstone in the mountains in Phayao to create Until becoming a Buddhist art that is beautiful and unique to the region from the history of Pho Khun Chueang which focused on gathering troops and training in military science and expertise in geography Combined with the location of Bo Sip Song forest, which is a good strategic point to defend against the enemy. because it is at a high point with a long slope of rocky cliffs You can see the general area of the city. And what was found from the traces on the stone slabs in Bo Sib Song forest, whether it was a stone throne that sat Phraya Chueang. Ancient paintings, traces of blades, spears, and swords, including settlements of the Phayao people that surround Bo Sip Song Forest. Therefore, it is assumed that this Bo Sip Song forest is the location of the royal army or vanguard which trains soldiers in enemy battles and for use in the defense of cities as well as being an important point in strategizing the city plan of the Phu Kam Yao Kingdom. It is also assumed that the Bo Sip Song forest area May be the habitat of ancient humans. From the discovery of stone axes and paintings on slabs in Bo Tsong Forest.