About 20km from Muang Prachin Buri is Si Mahosot Ancient City. It boasts Thailand's oldest replica of the Lord Buddha's footprints and also the country's oldest offshoot of Phra Sri Maha Bodhi Tree in India under which the Lord Buddha meditated and attained enlightenment 2,600 years ago.
Located about 3km southeast of Muang Si Mahosot archaeological site, Sa Morakot is a complex of ancient Buddhist monuments. It comprises several layers of structures dating from the 9th century. The Lord Buddha’s footprints have been carved onto laterite, and in the middle is a carved dhamma wheel with a swastika-shaped hole. It is considered the country’s biggest and oldest Buddha footprints. Archaeological evidence and a stone inscription found there suggest that the footprints and the ruins of the hall enshrining the footprints, a laterite front yard and walls date to the 9th century. However, the newer structures, including the front gate, a stupa and a long corridor, have the same floor plan as an ancient Khmer hospital building known as the arokaya sala , commissioned by King Jayavarman VII. These characteristics and the unearthed sculptures belonging to Bayon art suggest that these buildings were built during the 12th-13th centuries. North of the site are two ponds named Sa Morakot and Sa Bua La. Nearby is a hall displaying exhibition boards on the history and archaeological details of Muang Si Mahosot.
Muang Si Mahosot was one of several cities in Thailand dating to the Dvaravati period (5th-12th century). It had one of the 111 arokaya sala hospitals, commissioned by Khmer King Jayavarman VII.