Mývatn has so many things to do! The weather hasn't been ideal - rainy/snowy (no real accumulation though) and foggy. But we made the best of it and still had a blast.
Mývatn lake is about 37 square kilometers (14.29 sq m). It has around 50 islands and islets. The average depth is about 2.5 m (8.2 ft), and the deepest is about 4 m (13.12 ft). The name comes from the many midges (type of insect) in the area. It is known for its diverse bird population, and more species of duck live in this area than any other place on earth.
Mývatn is located on the boundary of the North American and Eurasian plates, and these plates drift apart 2 cm (about .75 in) per year. Lava fills the rift, and this has caused much volcanic activity in the area.

Stórgajá
Stóragjá is a neat lava cave right at the junction of Routes 1 and 848 next to the lake. It is a fissure that formed after the lava from Jarðbaðshólar (a crater row and volcanic fissure from the Krafla volcanic system) formed 2700 years ago. The Stórgajá fissure formed in 8000 year old lava. During the Krafla fires (1975-1984, extreme volcanic activity at the Krafla caldera that includes earthquakes, ground fissures and small lava eruptions), the original temperature of 26 degrees C (78.8 F) at Stórgajá increased to a suitable bathing temperature. However, the temperature has cooled back down to its original state before the Krafla fires.

Krafla
100,000 years ago, a volcanic cone in the area caved in after erupting. The resulting caldera is now filled with younger volcanic material. Below at a depth of 3 km (1.8 m), there is a magma chamber. Magma flows into the chamber, which expands and raises the ground. The chamber then bursts, and the magma flows through underground fissures to the north and south. The pressure in the chamber decreases quickly, and the land drops back again quickly. Volcanic activity occurs every few centuries. The Mývatn fires occurred in the late 18th century, and one event that occurred created the beautiful Stòra-Viti crater. Volcanic activity occurred about 250 years later on the 1970s with the Krafla fires.
We actually couldn't make it all the way up to Krafla, which was a little disappointing. The snow was too deep and the mountain too steep to safely make it up there. Oh well...next trip I guess!
We drove by a geothermal power plant up near Krafla. It was interesting how the pipes snaked across the land and rose to admit cars through. Also, it seems like a matter of time until that power plant is destroyed, right?

Hverir/Námafjall
Hevrir is the largest sulphur hot spring in Iceland. It's also got some of the warmest temperatures found in Iceland...the soil is boiling! A warning - it is very stinky there. Like an overcooked rotten egg type of smell. I think my favorite part of this area is the color you see! The soils are so incredibly beautiful. You see reds, oranges, yellows, greens, blues, whites, blacks, greys, and I'm sure there are more. The flora is also very vibrant. It was really neat to see and hear the steam coming up from the earth. Don't we live in such an exciting planet?!
Námafjall was the giant mountain next to Hverir. It had hot springs along its inclines, and it was neat to see the grass areas contrasting the snow.

Grjótogjá
Like Stórgajá, Grjótkgjá is a lava cave that formed from lava from Jarðbaðshólar. It used to be a really popular hot spring to bathe in, but the Krafla fires 1975-1984 raised the temperature above its original 42 degrees C (107.6 F) to one that is too hot for bathing. The temperature is slowly falling, though. The ceiling has recently been deemed unstable, and it is advised only to enter at your own risk. Which, of course, we did. 🙂

Hverfjall
We climbed a volcanic crater! Hverfjall is a crater that is around 2700-2900 years old. It is about 1 km (0.6 m) in diameter and about 140 m (460 ft) deep. The round shape is disrupted by a landslide that occurred during eruption. It is a tephra crater, and this type is fairly uncommon in the world. The Lúdentarskál crater southeast of Hverfjall is also a tephra crater, though much older.
It was snowing pretty well and a bit windy, but we did it. We climbed from the parking lot on the northern side, which is supposed to be an easier climb as it's not as steep. It did get steep toward the top, and the difficulty was multiplied by the fact that there was around 4-6 inches of snow on the ground. It took us about 20 minutes to leisurely walk up to the top (stopping to get our breath several times - we both have asthma that's aggravated by cold air, and I'm out of shape!).
But man was it worth the climb when we made it to the top! You could probably have a heck of a view on a clear day. It was foggy, and a windy snow had really started at the top, but our view was still amazing. It was hard to fathom that the giant crater we climbed and were looking into was once a peak before it began erupting and collapsed in on itself. It would have been nice to walk around the entire top, but there was just a lot of snow on the ground, cold windy snow blowing in our faces, and a retiring sun that kept us from doing so.

Dimmuborgir
Dimmuborgir is a really neat lava field just south of Hverfjall. It is a pool of lava about 2 km (1.2 m) in diameter that was formed by an eruption from Lúdentarborgir. The lava pool then drained into Mývatn lake and left behind tall towers of lava. It is thought that these towers of lava were formed when steam rose through the molten lava and cooled them. Lava slag coated the towers when the surface sunk around them, leaving vertical etchings. Lava formations similar to Dimmuborgir have been found off the coast of Mexico, but there are no known lava formations such as these on dry land anywhere in the world except for in the Mývatn area.

Vogafjós
We had heard many great things about Vogafjós ("Cow Shed"), although we had heard it was pricey. Honestly, everything in Iceland is pricey. You kind of choke up a bit when you find a nice pair of winter gloves that are $70. But we also knew that Vogafjós had smoked lamb, as well as viewing windows into their shed where they milk their cows at about 7:30 a.m. and about 5:30 p.m. Man, I'm so glad we came. It was an incredible meal with great service, and the employees are very helpful and nice. We had an appetizer of smoked lamb with cottage cheese, blueberry jam, and geysír bread (bread that is baked for 24 hours in a container in the ground using geothermal heat). The smoked lamb was insane. We love anything smoked, and the lamb absolutely did not disappoint. For dinner, we split the following: pan-fried Arctic char with a garlic potato cake and salad with homemade salad cheese; beef burger with homemade mozzarella, a smashed baked potato, and a salad with homemade salad cheese. For dessert, we split the following: ice cream (1 mixed with chocolate and made from geysír bread and the other made with Angelíca herbs found around the lake) and Vogafjós cake (chocolate cake with caramel and pecans). We also had hot chocolate with cream, and that was perfect after our cold day. Everything was so delicious. If you're ever in the Mývatn area, you certainly must check out Vogafjós.

Tomorrow, we spending a couple hours in Mývatn and then heading to Egilsstaðir. Cross your fingers that the mountain passes between here and Egilsstaðir are good! Right now, the road website is showing that they're in decent shape. We haven't had too much accumulation, so let's hope they're still alright.
Enjoy a photo of some sheep, and have a good night!