Historic Town of Sukhothai and Associated Historic Towns - Credit: Wikimedia Commons
The Historic Town of Sukhothai and Associated Historic Towns is a UNESCO World Heritage Site which consists of Sukhothai historical park, Kamphaeng Phet historical park and Si Satchanalai historical park. These historical parks preserve the remains of the three main cities of the Sukhothai Kingdom which flourished during the 13th and 14th century CE. The Sukhothai Kingdom is viewed as having been the first of the Thai kingdoms. Read more on Wikipedia
Source: en.wikipedia.org