The Fine Arts Department has restored the large 12th-century Khmer Wat Phra Si Ratana Mahathat, considered one of the city's oldest. During Lopburi's heyday, it was the town's largest monastery, a fact clearly shown on a map drawn by French cartographers in 1687. A tall laterite tower still stands and features a few intact lintels and some ornate stucco. There is also a large wíhaan added by King Narai. Several chedi and smaller towers dot the grounds.