Sri Satchanalai Historical Park is located in Sawankhalok (สวรรคโลก), a present-day amphur in Sukhothai. Its old name was Sri Satchanalai and the park, as well as the former city, are still referred to by the earlier name. This old princely city was a former satellite city from Sukhothai and is located along the Yom River. It was founded in 1250 AD and in the 13th and 14th centuries served as a residence for the crown prince. The park, which is depicted on a set of four Thai postage stamps issued in 1993 to mark the annual Thai Heritage Conservation Day, includes the ancient ruins of Wat  Naang Phaya (วัดนางพญา), Wat Chang Lom (วัดช้างล้อม), Wat Chedi Jed Thaew (วัดเจดีย์เจ็ดแถว),  and the hilltop temple Wat Khao Phanom Phleung (วัดเขาพนมเพลิง), which lies at the end of a steep laterite staircase. 回