All three accommodations have tent sites, guest kitchens, and showers. Unless you are staying at Húsadalur, you must bring a sleeping bag. To beat the summer rush, make sure to book at least a few weeks in advance.
Básar (tel. 854-2910), run by and booked through Útivist (tel. 562-1000; www.utivist.is), comprises a small hut (sleeps 23) and a large hut (sleeps 60). Both huts are open May through October, and a warden is on-hand. From November through April the smaller hut remains open, but you need to get a key in advance. Básar is notorious for late-night partying on summer weekends because it's most easily accessible to 4WD vehicles. Sleeping-bag accommodation is 2,000kr ($32/£16) per night.
Húsadalur (tel. 580-5404; www.thorsmork.is), maintained by Reykjavik Excursions , is open from June 1 to September 9. It has the best facilities of the three accommodations, with an extensive compound of huts, cabins, a cafe lounge, and a geothermal pool and sauna. The cafe, open until 9pm, sells drinks, skýr, candy, soup, and basic sandwich supplies. Unlike the other two accommodations, some sleeping quarters have private doubles and made-up beds. Sleeping-bag accommodation in a twin room is 2,300kr ($37/£18) per person per night, and cottages sleeping 1 to 5 people are 7,500kr ($120/£60). Sheets and towels are available for rent. The pool is included, but a sauna and shower is 500kr ($8/£4). Of the three huts, Húsadalur has the least picturesque location, but the best hiking areas are within easy reach. Húsadalur is also the most peaceful after hours, since quiet time is more strictly enforced.
Skagfjörðsskáli (tel. 893-1191), also known as "Langidalur" or simply "Þórsmörk Hut," is run by and booked through Ferðafélag Íslands (tel. 568-2533; www.fi.is). The hut, open from mid-May through September, sleeps 75 people in three well-packed rooms. Sleeping-bag accommodation, at 3,000kr ($48/£24), is more expensive than the competition. A tiny store sells chocolate, cookies, soap, and a few other necessities. The Krossá River is just outside the hut.