Scott C.
Google
Unfortunately for us, we were too early for most of the spring blooms (the park was not officially open, and we didn't need to buy tickets), but it was not hard to see that it is a spectacular place when the flowers are out. There are even little "forests" for the kids to play in. We will be back at a better time, for sure. Well worth the little detour to visit.
EDIT / UPDATE
We returned later in the season and the grounds were lovely. Plenty of flowers out to enjoy and more importantly, the buildings were open to visit inside. The "castle" is lovely and I am so glad to have been able to see it. There was an art exhibit inside (it was only so-so), in addition to the historical exhibit (well worth the time to read). I think we will return for out third visit later in the fall when the leaves have turned colour.
Bottom line: We made two trips from Oslo (14 hours total driving each time) to see this place and are planning a third trip, so I think it is very high on out list, based on our willingness to undertake such a long trip.