Thirty-five miles north of Sukhothai (about a 45-minute drive) lies the ruins of the town of Si Satchanalai, a satellite city of the Sukhothai Kingdom, built around the same time. The ride to Si Satchanalai is kind of interesting. On the way, you'll pass lots of rice paddies and sugar cane fields, periodically occupied by locals with big straw hats. For some reason, there are also a lot of dogs wandering around here, many of which seem to like sunning themselves in the middle of the road. So if you are driving, be prepared to honk and swerve!
Wat Chang Lom, seen here, is one of the best sites at Si Satchanalai.