The main target for most visitors on the northern side of the park is this impressive glacier, which can be reached along a scenic 23km road from Olden. Once you reach the car park, it's a 5km return walk up a steepish path to the glacial face; alternatively, there's a longer, gentler cart track. There are currently no guided walks on the ice itself due to dangerous crevasses, but there are RIB tours on the lake.
For the last century or so, the traditional way to get up to the glacier was in a pony-cart, but these have now been replaced by troll cars operated by Oldedalen Skyss, which look rather like giant golfing carts (195kr per person). From their turnaround point, there's still a 15-minute hike on a rough path to see the ice. You can book transport at the Brikksdalsbreen visitors centre, but it's worth reserving ahead, as demand often outstrips supply.