Sukhothai (สุโขทัย) is a small city (population 35,713) which serves as the capital of Sukhothai Province, in lower Northern Thailand. The name translates as "the dawn of happiness".
The city is a popular tourist destination because it is located near the ruins of the ancient city of Sukhothai, which was the Thai capital during the 13th Century A.D. that Siam took from Khmer Empire .
Sukothai only has a small bus station, but the city can be easily reached from the North, South, East and West.
From Mae Sot: Minibuses run regularly from the station behind the market. The journey takes about 3 hours, passing through Tak on the way. 130 baht.
From Phitsanulok: Frequent buses operate from the main bus terminal and take about 1 hour for the 58 km trip.
From Bangkok
By Bus : There are direct buses from Bangkok Mochit Terminal and takes 7 hours, including some stops at Bus Terminal of major cities on the way.
By Train : Take the (express) train (7 hours) to Phitsanulok and go by bus from there (1 hour).
From Chiang Mai: Buses from the main bus terminal take about 4 hours. The cheaper local buses make many stops and take about 5 hours.
The best way to see the ruins in the Sukhotai National Historic Park is by bicycle. These can be rented from a shop opposite from the main park entrance.
The purple #1 songthaew travels to and from the bus station, which is about 3 km out of town. They run the length of Thanon Charodwithitong. The fare is 10 baht.
The large blue songthaew to Old Sukhothai leaves from a bus stop on Thanon Charodwithitong about 100 meters west of the bridge. It stops about 750 meters from the entrance to the central zone of the historic park. Fare: 20 baht.
Old Sukhothai (Sukhothai Muang Kao)
Located 12 km to the west of today's 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 heavy restoration is worth noting, since with some ruins and Buddha figures it can lead to a feeling that it is a little over-sanitised, especially in the central zone. The other zones are much less "restored" and trips down unmarked tracks can lead to ruins in their untouched state.
The whole site covers an area of approximately 70 square kilometres and is divided into 5 zones. The central zone contains the majority of the ruins and a museum. As of December 2008, admission is now 100 baht (6 am to 6 pm) plus extra for vehicles, including bicycles. Maps can be bought at the ticket office for 3 baht. The other zones (north, east, south and west) have separate fees of 100 baht, or a combined ticket for all zones and the museum is 350 baht. Bicycles are the favoured mode of transport, though it is perfectly feasible to walk around the central and northern zones in 6 hours or so. Bicycles are available for rental at numerous places near the songthaew stop. There is also a 20 baht guided tour by electric tram available.
Article source: http://wikitravel.org/en/Sukhothai