Hoi An, Vietnam
Once a thriving port town, Hoi An would probably look much different today had the Thu Bon River not silted over in the 19th century. Now, it is virtually traffic and air pollution free, as well as boasting some very grand architecture. Such clear views come at least in part to the town’s tradition of turning off most electric lights in favor festive, colored lanterns on the 14th day of each lunar month.