Jostedalsbreen is the largest glacier of continental europe (only Vatnajokull in Iceland is larger) with an overall area of roughly 900 km². Many sidearms are protruding from the glacier extending into the valleys below.
There are several posibilities to access the glacier, the most popular being Nigardsbreen on the eastside and Brigsdalsbreen on the westside. Due to the bad weather we only went to Nigardsbreen which has a small lake in front of the glacier. A short trail (one hour oneway) leads from the visitor center to the bottom of this huge sidearm. You can shorten this distance by taking a boat trip on the small lake.
There is not much else to do unless you take a guided tour on the glacier. It's probably worth it if the weather is good. They usually go up Nigardsbreen until they reach the plateau of Jostedalsbreen.