Dogs must be leashed between April 15 and August 20.
Hennings (probably named after someone named Henning) is a relatively steep natural singletrack off the side of Drammen Skisenter. As with other Norwegian trails, you are not required to pay for access, but for most people it will be worth it to pay for the lift ride to the top rather than climbing under their own power.
On your way down, pay attention to the signs. Many sections of the trail are split in two parts, one for hikers and one for bikers. To avoid accidents, don't ride on the hiker only sections!
Apart from two short wooden bridges, the trail is all natural and relatively worn by water and use. It is a bumpy and technical ride that keeps you focused the whole way down. When you see signs with black arrows pointing downwards, you may want to get off your bike and survey the upcoming section before you take it on the first time.
The trail spits you out at the back of the parking lot of the ski center, rather than ending up in the hub out front of the visitor center.