This mtb track has it all. Well, perhaps no rock gardens, but these can be substituted for root gardens. this place is not far from Krk. If you happen to be in the area and like MTB, I definitely suggest to do this round trip. Altitude gain is about 600 hm, length 22 km.
I drove it clockwise, the track runs around a reservoir. Along the North to the North East side the single track is covered with gravel and it runs close to the waterlines. This section has sharp corners, short steep climbs and descents between an otherwise flowy trail. along the South side the track is wider but still mostly covered with gravel; it has more and longer climbs and this takes you away from the waterline.
The West side is brutal: it has very steep sections with forest ground, in this case it means loose stones, roots, mud, erosion ditches and occasionally a short grassy / marsh section. Plenty if diversity I would say.