• Wat Si Chum is one of the largest and most mysterious temples in Sukhothai Historical Park, Northwestern Thailand.

• Here there is a massive mandapa (pillared hall for public rituals) in the middle of the complex which was built in the late 14th century by King Maha Thammaracha II.

• Inside the mandapa, there is a huge 11 meter wide and 15 meters high seated Buddha image called "Phra Achana".

The Mandapa has a square base of 32 meters on each side and 15 meters high, and its walls are a meter thick.