A single late Ayutthaya Wiharn built to house the 15th Century Phra Mongkol Bophit, a huge bronze Buddhastatue, 9.5 meters accross the lap, and 12.45 meters high, not including the pedestal.
Compared to the surrounding ruins, this is a new temple. Be sure to take off your shoes and see the Buddha image inside - among one of Thailand's largest.