Sukhothai Historical Park (อุทยานประวัติศาสตร์สุโขทัย, map) (14 km to the west of New Sukhothai). This was the capital of the Sukhothai Kingdom from 1238 to 1438 and contains many ruins from that period.
Its importance has been internationally recognised and it is now a UNESCO World Heritage Site. The old city is a popular tourist attraction, and the site has seen much restoration since the 1960s. It is well maintained, exceptionally clean and well furnished with vendors, though with only a minimum of touts.
The province’s temples and monuments have been restored and the UNESCO-listed Sukhothai Historical Park covers a wide area with numerous sites. Other interesting places include Ramkhamhaeng National Museum (map), Ramkhamhaeng National Park (map), Sri Satchanalai National Park (map).
The whole site covers an area of approximately 70 km2 (~27 square miles) and contains 193 ruins. The park is divided into 5 zones namely: Central, Eastern, Southern, Western and Northern Zones. The central zone contains the majority of the ruins and a museum. Maps are free at the ticket office. Every zone has an entrance fee of 100 baht each, but the combined ticket for all the zones is not available anymore as of January 2020.
It is feasible to walk around the central and northern zones in 6 hours or so. There is also a 60-baht guided tour by electric tram available. The best way, however, to see the ruins is by bicycle. These can be rented from a shop opposite from the main park entrance.
The best time to see the ruins is mornings when it’s a little cooler and before the buses arrive, at noon when they have lunch, or after 16:00.
Also, if photographs are important, remember most Buddhist temples face east designed to be approached from the east so after midday you are more likely to be taking pictures into the sun.
Si Satchanalai National Park (map) offers trekking routes through waterfalls and caves. There is Tad Dao Waterfall, originating from the Tha Pae stream. Thara Wasan Cave (map), with fantastic stalactites and stalagmites, is about 1.5 km (0.93 mi) away from the park’s office. Wildlife is found here, including hundreds of thousands of bats. Tad Duan Waterfall, about 500 m from the office of the park, is ideal for swimming.