Despite the lack of a view from the summit, there are marvelous views all the way up, particularly at a marked viewing area, 10 or so kilometers before the top. Unlike Khao Yai National Park, 200 kilometers from Bangkok, Doi Inthanon doesn't have a whole host of nature trails. There are 2 designated trails - there are others but they're not marked or 'advertised', so if you do want to spend some days here, it would be interesting to find more trails. If you look at the map given, there appears to be a trail connecting the summit to Sriphum Waterfall and also Mae Ya Waterfall (outside the park) to an area inside the park but I have absolutely no idea about these! happy searching...think about wearing long trousers if it's been raining and you go serious trekking because of leeches!). You could perhaps visit the bird watching center and see if you can hook up on a walk.