Wat Pho Chai (Luang Por Phra Sai) is a royal temple housing the revered "Luang Por Phra Sai" Buddha image, a symbol of Nong Khai. Originally called Wat Pee Piu, it was renamed Wat Pho Chai during the Rattanakosin period and elevated to a royal temple. The temple houses "Luang Por Phra Sai," a golden seated Buddha image highly revered by the locals. According to legend, three princesses of the Lan Chang kingdom created three Buddha images named Phra Serm, Phra Suk, and Phra Sai. During King Rama III’s reign, these images were transported from Vientiane to Nong Khai, but Phra Suk sank into the river during a storm. Phra Serm and Phra Sai were enshrined at Wat Pho Chai in Nong Khai, with Phra Serm later moved to Wat Pathum Wanaram in Bangkok. Each year during the Songkran festival, a ceremony is held for locals and visitors to bathe the Luang Por Phra Sai Buddha image.