Wat Sao Thong Thong is a third-tier royal temple of the common type. It is situated on France road between Narai Ratchaniwet Palace and the envoy reception house. In a map made by French engineers, the site is described as a residence for Persians, with a mosque for Islamic religious rites.
It is believed that this is the present location of the royal assembly hall. In addition, there is Bijoux building, a small two storey L-shaped srtructure that was possible named after a Persia gems merchant called “Bijoutier” by foreigners. This temple is unique because of it’s late Ayutthaya architecture.