Get to Wǔyí Shān for the "Da Hong Pao tea" and scenic routes through the national reserve. The place is considered to be a tourist spot, but the infrastructures are kinda not worth the required price (you'll find mostly hotels and there is no youth hostels, English is almost not spoken there).
Nevertheless, this place, being aside of the most tourist-y routes is totally recommended for a few days of exploring the national park area, tasting all kinds of “Oolong tea”:http://en.wikipedia.org/wiki/Oolong_tea and eating all kinds of local mushrooms. Truly, I have never seen so many kinds of big mushrooms in my soup!
The relief is kinda similar to Guilin, meaning that some of the rocks had undergone the erosion process by water and weather. The biological variety (according to a Wikipedia) is characterized by an astronomic numbers of counted kinds of species. The territory had been inhabited at least 4000 years ago and the historical and spiritual flashbacks refer to the ancient “Minyue Kingdom”:http://en.wikipedia.org/wiki/Minyue, “Taoism”:http://en.wikipedia.org/wiki/Taoism and “Neo-Confucianism”:http://en.wikipedia.org/wiki/Neo-Confucianism.
The closest big train hub is Shangrao. However, buying tickets there is not very easy, so proceeding to one of the really big cities (such as Nanchang) might be a really good idea.
In the natural reserve you’ll find lots of interesting spots and some arrows, saying “off the tourist route” – trying some of them may lead you through the very picturesque walkways :)