Phu Phan National Park (อุทยานแห่งชาติภูพาน) is 30 minutes from downtown Sakon Nakhon. The forest park is located along Route 213, about 9 kilometers past Namtok Kham Hom waterfall. If you stay on Route 213 past the park, you only need to travel another 15 minutes to reach Wat Phra Phutthabat Namthip, with its grand courtyard of large, white Buddha statues.
The two main attractions of Phu Phan National Park are its mountain cliff view (especially at sunset) and its nature trail. The scenic cliff is near the Camp Site (a beautiful place to stargaze at night), and can be reached by car. Just keep driving past the Welcome center, and follow the signs. According to legend, two workers at the park fell in love, even though the young woman already had a husband. They met at this cliff in order to try to work something out, but couldn’t come to an agreement, so the man leaped from the cliff to his death. It is now called Nang Mern Cliff (ผานางเมิน), which roughly translates to the cliff of the girl who turns away.
The Phu Phan National Park nature trail is located to the left of Nang Mern Cliff. It's a rough but easily walkable trail through a section of the forest. Many of the trees are labeled with signs, some with English information. Other signs have QR codes, which take you to a Thai web page, but which can easily be translated into English.
During the rainy season, the Phu Phan forest is very lush, but it is also nice to visit during the cold season, where you can walk the trail on a crunchy bed of fallen leaves, while admiring some of the other trees that still retain their greenery. There are also less bugs to worry about when trekking during the rainy season. Many families of monkeys live throughout the Phu Phan forest, and you will occasionally see them in this area, along with different species of birds.
Whenever we have visited the park, we have entered for free. However, some people have reported paying a small fee for entrance. It may depend on the time of year that you are visiting. So, do have a little cash on hand, just in case you need to pay an entrance fee.