It is said that the builder of this vihara (temple hall) was a man named Sam Chom, who constructed it simultaneously with one of the surrounding chedis (satellite stupas) located behind the vihara. As a result, the vihara was named after its builder — Vihara Sam Chom. The vihara is situated to the east of the Phra Borommathat (Great Stupa), directly across from the cloister gate. Before entering the vihara, one can see a relief sculpture of the Earth Goddess wringing water from her hair on the front wall.
Inside the vihara enshrines a plaster Buddha image known as Phra Chao Si Thammosokarat, believed to be the king who commissioned the construction of the Great Stupa. The image is in the Maravijaya posture (subduing Mara) and is adorned in the attire of an ancient monarch, complete with a tall crown. It reflects the craftsmanship of the Ayutthaya period.
Due to the name of this Buddha image, “Phra Chao Si Thammosokarat,” local residents sometimes refer to Vihara Sam Chom as "Vihara Phra Chao Si Thammosokarat." Behind the vihara stands a three-arched gate that houses Buddha images in the Maravijaya posture and serves as a repository for the relics of royal family members and nobles descending from King Taksin of Thonburi. On the gate itself, there is a relief depicting the episode of the Buddha cutting his topknot in preparation for ordination.
