Wat Chaiyo Worawihan or Wat Ket Chaiyo is located on the west bank of the Chao Phraya River, approximately 18 kilometers away from Amphoe Mueang Ang Thong, on Ang Thong Sing Buri route. This is the second-class royal monastery. Formerly it was a small ordinary temple constructed in the Ayutthaya period with the unknown building date. Later in the reign of King Rama IV, this temple was noted when Somdet Phra Phutthachan (To Phromrangsi) a revered monk of Wat Rakhangkhositaram in Thonburi constructed a large seated Buddha image in the posture of meditation made of white plaster.
In the reign of King Rama V, His Majesty the King went to worship the image and had Wat Chaiyo renovated in 1887 but the vibration from ramming piles of the wihan caused the large Buddha image to collapse. The king then commanded to build a new large Buddha image following the pattern of the large Buddha image at Wat Kalayanamit. The new one has the lap width of 16.10 meters and the height (from radiance to feet) of 22.65 meters and was graciously named Phra Mahaphutthaphim. There was the biggest celebration for the image ever held in Ang Thong at that time. The molded statue of Somdet Phra Phutthachan (To Phromrangsi) constructed in 1894, having the lap width of 5 meters and the height of 7 meters, has been enshrined in the wihan facing the Chao Phraya River.
The large Buddha image housed in this wihan is larger, more elegant, and more remarkable wihan than any other, therefore, Buddhists from various parts of the country have continuously paid homage to this image. In front of the wihan, the ubosot facing the Chao Phraya River was constructed using the magnificent Thai architectural design. Inside the ubosot, there are mural paintings depicting scenes of the Lord Buddhas chronicles painted by the artisan in the reign of King Rama V, and the molded statue of Somdet Phra Phutthachan (To Phromrangsi) from Thonburi. At present, Wat Chaiyo Worawihan has been renovated to exhibit its distinctive beauty.