The history of Wat Klang, also known as Wat Pho Si Sattha Tham, dates back to before the establishment of the Rattanakosin Kingdom. The Ministry of Education officially recognized it as a temple where monks reside on January 30, 1957. The temple was originally called “Wat Pho Kham,” but the local community gradually began to refer to it as “Wat Klang” due to its central location between Wat Nuea and Wat Tai. Later, during the tenure of Phra Sithitakorn, the first district chief of Manohrom, the temple was renamed “Wat Pho Si Sattha Tham.” According to legend, the revered Buddha statue named Luang Por Sam Si depicts the Buddha in the posture of subduing Mara. This statue is known for its stunning features, showcasing a blend of Buddhist art from various eras. It is believed that Luang Por Sam Si was created during the Chiang Saen and Sukhothai periods. There are tales passed down through generations that Luang Por Sam Si was originally named “Luang Por Yok.” This name originated because, in historical times, Manohrom district was a major hub for boat transportation, leading to a high volume of river traffic. The temple’s location by the Chao Phraya River enabled passing boats—both passenger and cargo—to offer their respects by waving hands in salutation. Some boats would even scoop water from the river in front of the temple to sprinkle on their vessels for good fortune, as it was considered sacred water from Luang Por Yok. Occasionally, boat travelers would witness miraculous events, such as the sighting of Luang Por Yok slightly swaying, which sparked great astonishment among observers. Particularly, boatmen would encounter this phenomenon frequently, thus giving rise to the name “Luang Por Yok.”