Haiensa temple is a very nice place to visit. The limite of the WH site seems to be limited to four wooden building atop the temple complex, which are depositories of the Triptika Koreana. I went in may 2010, not knowing what to expect, since the internet site anouned the site beeing closed for the year. In fact there is no guided visit, but the site not totally closed. You can still view the wooden building from outside. And you can get a glimpse at the woodblock though the windows (slatted windows thourgh which air can penetrate).
I enclosed a picture take through this window. There are signs banning photos, but many of the Korean tourists did not seem to care.
The rest of temple compex is completely open, as is the mountain trails around which allow very nice walks.
I was there on a sunny Sunday afternoon, the temple was overflowed by Korean tourists. But in the late afternoon, the place emptied. And in the evening, the place was almost empty.
You can stay the night in various temple lodge, or to a bigger hotel close by. The village nextdoor is full of nice restaurants.