Thirty kilometres west of Si Saket via Rte 226 in Amphoe Uthumphon Phisai, Prasat Wat Sa Kamphaeng Yai, built as a shrine to Shiva, features four 11th-century prang and two 'libraries' built of sandstone and brick. The prang have lost their tops, but many lintels and other carvings remain. A new museum has been built, but it remains empty for the foreseeable future.
The ruined sanctuary can be found on the grounds of Wat Sa Kamphaeng Yai, the prasat’s modern successor. Also here is a massive statue of the former abbot, a giant gong and some amusing statues depicting what punishments may await people in the Buddhist version of Hell as a result of various misdeeds in this life. Hit your parents, for example, and you'll have enormous hands.
Minivans from Surin (60B, 1½ hours, frequent) to Si Saket can drop you right nearby. The train (16B to 69B, 45 to 75 minutes, seven during the daytime) is faster and more comfortable, but the station is 1.5km away.