Lonely Planet review
In the heat of the day, the coolest place in town is the Chiang Dao Cave, a complex said to extend some 10km to 14km into Doi Chiang Dao. There are four interconnected caverns that are open to the public. Tham Phra Non (360m) is the initial segment and is electrically illuminated and can be explored on your own.
It contains several religious shrines, a common feature of Thailand's caves, which are regarded as holy meditation sites. There are also some surreal-looking stalactites reminiscent of a Salvador Dali painting.
To explore the other caves – Tham Mah (735m), Tham Kaew (474m) and Tham Nam (660m) – we recommend that you hire a guide with a pressurised gas lantern (100B for up to five people), not because you aren't intrepid enough to go solo but because the guide service provides income for the local villagers. The guides point out the interior cave formations that have been named, yet another Thai cave tradition.
Local legend says this cave complex was the home of a reu·sĕe (hermit) for a thousand years, and that the sage was on such intimate terms with the deities that he convinced some tair·wá·dah (the Buddhist equivalent of angels) to create several magic wonders inside the caverns: a stream flowing from the pedestal of a solid-gold Buddha; a storehouse of divine textiles; a mystical lake; a city of naga (mythical serpents); a sacred immortal elephant; and the hermit's tomb. Such fantastical wonders are said to be much deeper inside the mountain, beyond the last of the illuminated caverns.
There is a temple complex outside the cavern, and a stream with huge carp and catfish you can feed (which handily counts as making merit via a donation). Vendors by the parking lot sell medicinal roots and herbs harvested in the nearby forests.