The Suzuki Midnight Sun Run starts on the road Engjavegur close to Laugardalshöll Sports Hall and the ice skating rink in Laugardalur. The race ends on a path by the old laundry springs in Laugardalur called "þvottalaugavegur". The race is mostly on paths. On the following picture you can view the start and finish area.
You can see the course map here.