Wat Thammachak Semaram is in Ban Khlong Khwang in Tambon Sema. The place used to be a religious site in the Dvaravati period. The important artefact here is a huge reclining Buddha image made of red sandstone that stretches from north to south. It is 13.30 metres long and 2.80 metres high. It dates from 657 AD. The head is south and faces east. The face is somewhat square and made of 4 sandstone slabs on top of one another. The body is composed of sandstone blocks stacked vertically. Moreover, there is an old sandstone Buddhist symbol in the form of a cartwheel. The bottom part is the face of a forest keeper. It is kept in a pavilion. Other artefacts include bronze Buddha images, fired clay images, glass beads, a fired clay loom, and a stone inscription tablet. They are on display in Phimai National Museum.