The list of UNESCO World Heritage Sites reads like a collection of humanity's greatest hits. Its timeless classics. The Great Wall of China. Old Havana. The Taj Mahal. Sukhothai is on the list, too. It was the medieval capital of the Sukhothai Kingdom and one of the places where Thai civilization came from. What's left is a spacious parkland of elegant temples and giant Buddhas.

In Thailand, the only thing that outnumbers the statues of Buddha are the photos of the king, so you start to take them for granted. But the big Buddhas at Wat Mahathat in Sukhothai cast a spell. Something about the expression on their faces. The smile. Not all sculptors get that smile right. Sometimes it comes off as goofy, or condescending, or even a bit sinister. But the smiles on the Buddhas at Wat Mahathat have a little sparkle. Like here they are, at the moment of enlightenment, and they're trying really hard not to laugh.

Or maybe those Buddhas are just smirking at all us tourists wheeling around on clunker bikes. The rental bikes are part of the Old Sukhothai Tourist Experience, along with bedbuggy guest houses and restaurants that serve Thai noodles and an "English Breakfast Set," whatever that is. The bikes are a good way to look around Sukhothai since the site is so vast, but they're real junkers with missing pedals and wobbly tires. We look kind of ridiculous riding those bikes, and the big Buddhas around here know it.