Hvannadalshnukur (pronounced KWANNA-dalsh-nyooker) is the highest peak in Iceland at 2110 meters. Prior to 2005, it had been stated to be 2119 but an official survey in 2005 revised this. It is actually the highest point on a crater rim of the volcano, Oræfajökull, located in extreme southeast Iceland only a few kilometers from the Atlantic Ocean. The volcano itself is massive, the largest post-glacial volcano in Iceland and, according to my research, only exceeded in mass by Etna as far as European volcanoes go. But this fact pales in comparison when you consider that Oræfajökull is but a small part of the massive glacier, Vatnajökull.
Vatnajökull (meaning Lake Glacier, named after sub-glacial lakes under its center) is the largest glacier in Iceland and the largest glacial ice cap in Europe. At approximately 8500 square kilometers, it is larger than all of continental Europe's glaciers put together. To give American's some idea of the size of this chunk of ice, it is a bit larger than the state of Connecticut. This glacier takes up 1/12 of the country of Iceland and contains approximately 3300 cubic kilometers of ice. The average thickness of the glacier is 400 meters with the greatest thickness being over 1100 meters. It is interesting that scientists believe it was not formed during the last great Ice Age but during a cold period about 2500 years ago.
Vatnajökull has had five recorded eruptions with the latest three coming in 1996, 1998 and most recently in 2004.
Iceland Meteorological Office story and photos
The 1996 eruption caused large floods taking out bridges and cutting off eastern and western Iceland from each other for a time. Oræfajökull has had two recorded eruptions in 1362 and 1727. The 1362 eruption was the greatest tephra fall in Icelandic history and caused the area's abandonment (the name means something like "glacier wasteland").
Hvannadalshnukur sits adjacent to Skaftafell National Park. Created in 1967, it covers 1700 square kilometers and lies on the west side of the peak between three of Vatnajökull's 46 outlet glaciers (Skeiðararjökull to the west, Morsarjökull to the north and Skaftafellsjökull to the east). To the immediate north of Skaftafell is a finger of land with amazing hikes and sites (see section below for details or click on the link in this paragraph). Skaftafell itself has worthy climbs of both technical rock and glacier and is an oasis of color and life in an area of southeastern Iceland that is so close to a massive drainage of the giant glacier where a huge amount of flat stream-filled sand dominates the coast. Skaftafell enjoys better weather and more sunshine hours than anywhere else in southeastern Iceland as it is protected from wind and rain by the volcano. Trust me when I say I spent several days in the park getting sunburnt while clouds and 60 mph winds whipped up on the mountain.
The climb to the highest point in Iceland is not technically challenging but as you would imagine there are a large number of crevasses to deal with when you have glaciers that come down to sea level. There are two main routes and they both have about 6600 feet of elevation gain and take a long day to accomplish. Both start on the western flank of the mountain. The Hryggjaleið route from the Virkisjökull glacier is used only until about mid-July and is then closed due to crevasses and an icy surface. The more-standard Sandfellsleið route starts a bit further south and is open most of the year. The latter route takes about 12 hours (8 hours up, 4 down). Even though it is not particularly technically challenging, please don't underestimate a climb of Hvannadalshnukur. Weather on the glacier can be particularly bad and completely opposite of what is happening below in the Park. Crevasses abound and guided climbs are recommended unless you have an experienced team in glacier climbing.
The first ascent of Hvannadalshnukur was on August 17, 1891 when a British man named Frederick W. W. Howell was guided up by locals Pall Jonsson and Thorlakur Thorlaksson.
Getting to Iceland is up to you individually although I can tell you that Icelandair flies to Reykjavik from 5 US cities: Minneapolis, New York, Boston, Baltimore and Orlando as well as most major European cities. All international flights fly into Keflavik Airport about 40 kms. west of Reykjavik. From there you can rent a car from Budget, Avis, and the largest car rental place there is Hertz. I would advise booking a car/truck early and don't be surprised by the ridiculous price you are charged. I found car rental in Iceland to be about 4 to 5 times what it would be in the US.
From Keflavik, you probably will need to head to Reykjavik for supplies. Take Road 41 from the airport about 40 km east into Reykjavik until the road turns into Reykjanesbraut. You will trend north now and the road will become Fyarðarhraun. Take a right onto Rafnarfjarðarvegur and follow north until the road changes names again to Kringlumyrarbruat. Go north still approximately 6 streets and turn right onto Listabraut. Take your first left and then pull in right into the parking deck. This is the Kringlan Mall and go in and go to the Utivist store located on the bottom floor. It's a general sports store but it has the best selection I found with fuel, dehydrated food, etc.
Once you get your supplies, head out the parking deck and turn right (north) and exit out onto the large east/west road on the north side of the mall called Miklabraut. Take the road east and follow signs for Highway 1 (also known as the Ring Road).
Take Highway 1about 320 kilometers east to Skaftafell National Park. Turn left at the sign for the Park and go about 2 kms. to the Visitor Center and Campground.
May to September with July and August being the most popular and best weather climbing months.