Phra Tamnak Khamyat is located in Tambon Khamyat, 2.5 kilometers west of Wat Pho Thong on Ayutthaya Pho Thong Road. At present only four walls of the royal residence remain. The 10x20 meters royal residence, made of brick and plaster, stands eminent in a paddy field. The artistic beauty still remains e.g. motifs around the window, front and back balcony, was painted in red soil and covered with wooden floor.
Regarding his diary about the trip on the Makhamthao River, King Rama V visited Phra Tamnak Khamyat in 1908, he understood that Krommakhun Phornphinit (Prince Uthumphorn or Khunluang Hawat) entered his monkshood at Wat Pho Thong and built this residence for his lodging during the Buddhist Lent since it was a strategic site. Having seen that the residence was exquisitely constructed, King Rama V then changed his mind. He realized that Krommakhun Phornphinit should not have had this residence built so exquisitely for a temporary lodging or a stronghold.