This Park is in Northern Thailand, about 8 hours drive from Bangkok and 3-4 hours from Chiang Mai. It is quite an isolated spot and upto now has managed to remain relatively free of tourists. That said, it is still a very popular spot with Thais and in peak seasons it can get quite busy. But this is Thailand, almost everywhere receives visitors whether Thai or otherwise.
Umphang National Park contains the stunning Tee Lor Su waterfall, one of the tallest in Thailand and I think also one of the most beautiful. It has many different parts and layers to it. It is possible to find small pools here and there to relax in away from the crowds. You can also climb parts of it quite safely. The trek I went on was excellent, although all tied up with a local resort. It included rafting, trekking(or 4x4 for the less energetic) and an overnight camp. Also another night's accomodation in the resort's bungalows was included.
I'm sure that more secluded and quieter treks are available but they're becoming increasingly difficult to find in ever popular Thailand. This was just about the best option I could find.
Please forgive the poor quality photos, I was quite tired!!! These are the only photos I can scratch together as I managed to drop my own camera in the water!! These were taken by my girlfriend's brother.
