After descending a series of steps, you arrive at the cave of Chiang Dao, a kind of underground gallery in the mountain. As you proceed on the walk, there are numerous statues and mini-temples to discover. I wouldn't have been able to understood much about them without a guide, though they're still interesting to see anyway.
The further you descend into the cave, the heavier and damper the air becomes. This continues right up to the part you can only visit with a guide and a lantern. I'll leave you to explore the rest for yourself; I didn't venture any further!
The area around the cave, cool and fresh beneath the trees, is nice to visit. Chiang Dao Cave isdefinitely a place to go and see in this region of Thailand. Plan to take half a day for the tour, then go for an elephant-back ride at one of the numerous centers located nearby.
I went on a three-day scooter tour of the Golden Triangle region, departing from Chiang Mai. I hadn't planned to stop at Chiang Dao, and visiting there was a nicely surprising experience. I had trouble finding accommodation in town, but the locals came to my aid.
The big surprise was the morning market, where people from the different ethnic groups of the area north of Chiang Dao (the Hmong, Lahu and Akha) all come together. It's colorful and very interesting, even if the people don't smile much! You mustn't miss visiting the cave, which is located amid temples and mountains permanently shrouded in mist. It was wonderful! And the tour, despite the guide's broken English, is very instructive. You need to be a bit of an acrobat to get down into the cave's depths and properly keep up with the guide's lamp!
The little added bonus: the very natural, countryside character of the region, which stands in contrast to the tourism and hustle and bustle of Thailand's south.
The minor drawback: you have to pay for everything at the cave, i.e. the parking, the entrance, the tour, and even an electricity tax!