The Ancient Site of Sa Kaeo, the Sacred Water Reservoir of the Ancient City of Si Mahosot, Si Mahosot District This large water reservoir is adorned with intricately carved motifs of auspicious creatures, a testament to ancient beliefs that it served as a holy water source for religious rituals, possibly aimed at ensuring prosperity. It is the only ancient water reservoir in Thailand known for its beautiful carvings. Si Mahosot, located in Prachinburi Province, was historically known as Kog Phip. With an age of over 1,200 years, dating back to the 6th Buddhist century, it was once a significant coastal port city. The area flourished as a center for the arts, culture, customs, and Buddhism. Si Mahosot was a major ancient city, exhibiting considerable development in art and culture from before the 11th Buddhist century. Due to its status as a coastal trading post, it engaged in commerce with China and India, absorbing cultural influences from Funan. Archaeological discoveries, including a plethora of beads in the Funan and Roman styles, dating from around 600 to 800 AD, alongside various animal carvings in the Amaravati style from the 7th to 9th Buddhist centuries, firmly establish Sa Kaeo as a site of significant historical importance.