Developped to be a new landmark since 2017 with various Buddha images but also a Luang Poh Hin image, the former abbot of Wat Nong Na built on the mountain, the Khao Phraya Doen Thong peak which culminates at 800 meters above sea level offers a nice view over the valley with the water reservoir formed by Pasak Chonlasit Dam and its long railway bridge. It is a particularly recommended spot to go to watch the sunrise. Whether you have a clear weather to see the sun rising and coloring the sky in pink and orange, or when you have a sea enveloping the valley, it is beautiful. Personally, I had a very cloudy sky without mist so I never really saw the sun which was well hidden but it was still a pleasant way to start the day.
There were plans to build a skywalk up there too, but so far the construction hasn't started. And that's not so bad news because a skywalk would attract a lot more people. There is a monk who lives up there alone. Be careful, the wind can blow very strong at the top.