On the way to Phu Chi Fah
, you can stop at Phu Sang Waterfall. It is not the fastest route to go to Phu Chi Fah from Chiang Rai but it is the most beautiful. The waterfall is at the edge of the road, on the right side, you can not miss it. It is part of Phu Sang National Park. There is also a small circular trail othat leaves behind the waterfall but as for me, it is not very interesting except for the small blue pool of hot water. It takes about twenty minutes and there is an entrance fee to pay. Up to you to decide if you do it, I did, the walk is nice but not a must do.
The waterfall alone does not justify coming from Chiang Rai but it fits well with a day trip to Phu Chi Fah and Doi Pha Tang.