The roofless building houses a very large Sukhothai-style Buddha statue called Phra Achana. The stone stucco image is in the Subduing Mara mudra, also known as Bhumisparsha or Calling the Earth to Witness.
The Phra Achana is the largest Buddha statue in Sukhothai and is 15 meters high and 11 meters wide. The Sukhothai style image with serene facial expression takes up the entire space. In the center of the mouth cap there is an opening that decreases in size towards the top, through which the image can be viewed from the outside.