Phra Chao Si Sumangkhai Haï Sok is the revered Buddha statue of Nong Bua Lam Phu Province, embodying the Meditative Posture (Maravichai). It is crafted from stucco and painted in gold, with a lap width of 180 centimeters and a height of 190 centimeters. This artwork reflects the Lan Chang style and is housed in the Uposatha Hall of Wat Phothi, or Wat Haï Sok, located in Ban Lam Phu, Tambon Lam Phu, Mueang District, Nong Bua Lam Phu Province. Constructed in the year 2106 BE, this statue is deeply revered by the local governor and the people of Nong Bua Lam Phu. According to stories handed down through generations, Phra Chao Si Sumangkhai, also affectionately referred to by locals as Phra Chao Yai, is a sacred Buddha image believed to work miracles for villagers in distress, alleviating their suffering and granting wishes upon their prayers in remarkable ways. Due to this sanctity, its fame has spread among the locals; even those living in distant towns regularly visit to pay their respects and seek blessings. Wat Phothi, or Wat Haï Sok, was founded around 2310 BE during the Ayutthaya period. At that time, the governor of Vientiane crossed the Mekong River to establish a settlement in the southern region near the Phu Phan Plateau, prior to 2310 BE, and erected the Phra Chao Si Sumangkhai Haï Sok, or Luang Por Si Vichai, for Buddhist followers to worship. The statue also presides over rituals such as the water-pouring ceremony (Phra Piphat Satya) and serves as the focal point for merit-making ceremonies before starting agricultural work each season.