Lop Buri (lŭp bo͝orē`), town (1990 pop. 40,190), capital of Lop Buri prov., S Thailand. Originally called Lavo, it was ruled by the Mons in the 7th and 8th cent. and by the Khmers from the 10th to the 13th cent. While Ayutthaya was the capital of Thailand, Lop Buri served as an alternate capital.