Wat Khao Kaew Worawihan, an ancient temple on the mountaintop in Sao Hai District

Wat Khao Kaew Worawihan, Sao Hai District, Saraburi Province, was originally a temple built by the people in 2171 B.E. during the reign of King Songtham. Later, King Mongkut traveled to pay homage to the Phra Phutthabat in Saraburi and also wanted to pay homage to the Phra Phutthachai. He stopped to rest his soldiers at the pavilion at Hin Lat of Wat Khao Kaew. He saw that this area was strategically suitable because it was located on a small mountain surrounded by beautiful nature and was peaceful, suitable for practicing Dhamma. He therefore ordered Chao Phraya Nikorn Bodin (To Kalyanamitra) to be the chief of construction supervision. He arranged for his staff to bring the upper part and construction materials from Bangkok to renovate and renovate the ordination hall, renovate and expand it to be larger than the original, build a new wall around the ordination hall, build a kuti on the north side of the chedi, and restore the chedi. He established Wat Khao Kaew as a royal temple and named it Wat Kirirattanaram. Later, Somdet Phra Maha Samana Chao Prince Vajirananavarorasa saw that the name of Wat Kirirattanaram was a Pali word, so he changed it to the Thai word "Wat Khao Kaew".