San Lak Muang (GPS: 17.0181, 99.70388; Thai: ศาลหลักเมือง ) is the City Pillar Shrine of Old Sukhothai, in the Sukhothai Historical Park, Sukhothai, Thailand. It is customary for every Thai town and city to have a city pillar shrine, which serves as the home of the tutelary spirit of the city. Having said that, the idea that this particular heap of bricks and laterite columns is Sukhothai's city pillar shrine is pretty recent, dating only to the time of King Vajiravudh (Rama VI, who reigned from 1910 to 1925), when the site was excavated.
During the excavation of this site, two laterite pillars were discovered at each of the four corners, and a pit at the centre. Also discovered was a stone stelae with undecipherable inscription. King Vajiravudh believed it to be an astrological chart of the city. These are some of the determinants to suggest that this was the city pillar shrine of Old Sukhothai, even though there wasn't any historical inscription mentioning it.