The interior of an old teak viharn (Buddhist assembly hall) in northern Thailand. Called the Viharn Nam Tan, it dates from the early 16th century and is believed to be the oldest wooden religious building in Thailand. It is a part of Wat Phra That Lampang Luang, near the town of Lampang. This wat (monastery and temple complex) is a fortified temple and regarded as the finest in northern Thailand.