Wat Si Chum [ the temple of the bodhi tree ] is a 13th C temple. The buddha image is covered in stucco and is seated inside a square brick Mandala building with a tapering wall structure which opens in the center of the top. Wat Si Chum is situated about 1,500 metres north of Wat Mahathat, with a moat serving as the boundary. Although there are only the remains of a small viharn and mondop, this wat is of importance.
The roof of the mondop has disintegrated, exposing an enormous seated stucco Buddha over 11 metres in width called Phra Achana. The mondop is 32 metres square, 15 metres high and the walls are 3 metres thick. A passageway in the inner left wall leads to a stairway to the roof. On the ceiling of the passageway are more than fifty engraved slate slabs, dating back to the mid 14th century, illustrating scenes from the Jataka tales, stories of the Buddha’s previous lives.