|The Khun Than mountain range of the Doi Khun Than National
Park forms a natural boundary between Lamphun and Lampang provinces. The
northern rail line to Chiang Mai runs through the longest rail tunnel in the
country, which is 1,352 metres long and takes five minutes to traverse. The
mountain has both virgin jungle and pinery.
Many tourists choose to walk from the Khun Than Station up
the mountain, a distance of about 7 kilometres. There are four rest areas on the
way. Visitors may also camp overnight but must provide for their own food. The
best time to take the trip is between November and February when the weather is
fine and cool.