The origin of the Chao Phraya River is located at "Pak Nam Pho" in Nakhon Sawan. It is one of the most significant strategic points in Thailand, where two major northern rivers—the Ping and the Nan—meet to create the famous "Two-Color River" phenomenon. At this confluence, the waters merge to form the Chao Phraya River, the vital lifeblood that sustains the country's central plains all the way to the Gulf of Thailand. This historic area is rich with tales of river trade and traditional waterfront lifestyles, and it is home to landmark structures such as the Pasan building and the Chao Pho Thepharak-Chao Mae Thapthim Shrine.