Sukhothai was the capital of Thailand from 1238 until 1438 and features the Sukhothai Historical Park, which was unaffected by last year's floods. This UNESCO World Heritage Site is filled with the ruins of royal palaces, Buddhist temples and historical monuments.
If you get there early enough you’ll enjoy the golden morning light and have the park to yourself, which makes for an incredible photo opportunity. The best way to tour the ruins in and outside the city walls is to rent a bicycle or a motorbike, which also gives you a chance to see the scenic countryside surrounding the old town. Bike rentals are available at the park gates.