Si Satchanalai Historical Park has been declared a World Heritage site.The old city of Si Satchanalai is considered the sister city of historic Sukhothai. While it offers similar Sukhothai era temples and monuments, it is much less visited than Sukhothai. The old city of Si Satchanalai is situated in present day Sukhothai province. There are historic monuments located inside and outside the old city walls. Inside the city walls important temples include : Wat Chang Lom, Wat Chedi Jet Thaew, Wat Nang Phaya.