The most exciting possibility is to book an organized tour at the tourist office for glacier trekking on Hardangerjøkulen, at 1,860m (6,101 ft.). These are available Monday, Wednesday, and Friday from July 1 to September 15. The tour takes 10 hours and costs NOK600 ($120/£60) per person, including a train ride to and from Finse.
A number of other tours are offered as well: rafting from NOK750 to NOK875 ($150-$175/£75-£88), river boarding (a new high-adrenaline sport involving a white-water trip downstream on a high-impact plastic board-cum-flotation device) from NOK730 to NOK810 ($146-$162/£73-£81), and a 2-hour moose safari for NOK450 ($90/£45). This latter jaunt is offered only on Thursday evening (when the moose can be seen) from July 1 to September 15.
Back in the center of town, but only in July, you can visit Geilojorget, a 17th-century farm, which is open daily from 11am to 5pm. Some old houses, 2 or 3 centuries old, have been moved to the site and are open for guided tours. You can see how farmers lived at the time and visit such buildings as a storage house or the cattle barn. Cultural activities are also presented at the time, including folk music shows. On-site is a cafe serving old-time dishes; if you've ever wanted to try a sour-cream cookie, this is the place for you.
Note: This information was accurate when it was published, but can change without notice. Please be sure to confirm all rates and details directly with the companies in question before planning your trip.