Pang Ah-Noi Waterfall is in Taskin Maharat National Park in Tak province. A really beautiful national park nestled in the mountains in-between Tak and Mae Sot. The waterfall itself is at the end of a nice hike through some isolated jungle with the biggest tree in Thailand called Ton Krabak Yai (ต้นกระบากใหญ่)
First a little bit about Taksin Maharat National Park which is off highway 1 before you get to Tak and half way up highway 12 to Mae Sot. It is a really beautiful drive up-hill into the mountains and there are a few gas stations along the way. The park is at about 1000metres above sea level so it is relatively cool all year round. I went in January and it was very cold at night, so I would suggest during winter you should take some warmth clothing for the night and early morning. It has a good sized multi-level camping area, good information centre with a professional park office/ team and some really cool cabins which have an amazing view over the mountains and valley below. Ton Krabak Yai is part of the park's lower-elevation dipterocarp forest. Evergreen and pine forests inhabit the park's higher elevations.
The park was previously named, 'Ton Krabak Yai National Park', for the park's enormous krabak tree. On 23 December 1981, the park was designated Thailand's 40th national park. It was later renamed Taksin Maharat National Park ("King Taksin the Great") in honor of King Taksin of the Thonburi Kingdom King Taksin was a bit of a legend. From what I have read, the guy was brave, intelligent and a great leader; he did however, according to some sources, have mental problems towards the end of his reign. He expelled the Burmese force, which sacked Ayutthaya, out of modern day Thailand and was instrumental in the founding of modern day Thailand. He was overthrown by General Chao Phraya Chakri of the present House of Chakri and subsequently was either executed or spent the rest of his days in the mountains of Nakhon Si Thammasat.
The hike to the waterfall takes you down into the jungle passed the big tree and then further down to Pang Ah-Noi waterfall (Namtok meaning waterfall in Thai - Thai name of the waterfall is:น้ำตกปางอ้าน้อย). It should take about 2-3hrs to complete the loop. You will start from the multi-level camping area and head down into the jungle for a few KM's; it feels really secluded but there is a good and fairly obvious trail to follow. The nature is really stunning here and there are many species of bird such as the Tiger Shrike, Forest Wagtail, and Chinese Pond Heron to name a few.
The trail was quite overgrown when I went down it and there are a few obstacles and jumps across streams but nothing dangerous or difficult. You will then come to the big tree Ton Krabak Yai (ต้นกระบากใหญ่) The park's main attraction is Ton Krabak Yai, a 700-year-old krabak tree measuring 50 metres (160 ft) in height and 16 metres (52 ft) in circumference. The tree is believed to be the largest in Thailand.
You then continue down the trail about another 2km through a winding jungle path over a few streams and some fallen trees. The path down to the waterfall is quite narrow and steep and when I was there I found some small leeches trying to crawl up my trainers for a feast. The waterfall is small but quite narrow and unique. I took my shoes off and waded in and the water was really fresh and the atmosphere was nice and cool. If you go right to the front of any waterfall always be careful of falling rocks that are pushed down the streams. If you look around the bottom of a waterfall you will see some large rocks, those rocks came down the waterfall and landed where you are standing, so I would never advice to stand at the bottom of a waterfall too long.
You then walk back up to the trail and back through the helipad which is quite cool to go and a take a look at. The trail to the parking area for the big tree is at the end of quite a steep trail. Once you get to the parking area, just follow the road back to the national park centre. You will go past quite a unique and old iron bridge as seen at the start of this article. A few good hike with a waterfall and massive tree thrown in. There are other attractions nearby as Pang Ah Yai Waterfall, Pha Khaw Pha Dang Cave, Mae Yha Pha Waterfall and some great higher altitude hiking into the mountains. Unfortunately I was only passing through so I only had time to do the above but the park rangers seem to be very helpful and a couple spoke some fairly basic but good English.
Below are some further pictures of the cabins and park.