Loy Krathong generally takes place over one or two days. In Chiang Mai, this turns into a three day festival, though there are events scattered over five or six days. The night of the full moon is known as Loy Krathong Yai. The night before is known as Loy Krathong Lek. In practice there is little to choose between them. The focus of celebrations in Chiang Mai is around the Saphan Nawarat Bridge that connects Tha Pae Road on the western side of the river with Charoen Muang Road on the other side. If you like crowds and a party atmosphere this is the place to come.