I got a request recently to give a Geologist's 'Field Trip Guide to Iceland'. Fortunately for you, I just finished putting one together... so let's chat geo-travel! 
A good trip to Iceland requires your own car and at least ten days to see everything. This guide is for a non-4WD, so I won't be sending you off into the highlands. If you do have highlands questions, feel free to DM.
Another quick note before I get into it: you'll be doing a LOT of driving and will be a bit tired, but I promise it'll all be worth it. I'm also starting you out right away... no breaks here!
Day 1: Arriving in Iceland. Assuming you're arriving from the USA, you'll be arriving VERY early (~5am). European flights are a bit more flexible, but tend to arrive a bit later in the day. You can get a rental car at the airport very easily.
Once you've got your car, head into Reykjavik. Your first geo-stop of the day will be at Thingvellir National Park. The nice thing about arriving early in the morning is that it won't be too crowded yet!
Day 1, Stop 1: Thingvellir National Park, Visitor's Center. There's a great little 3D map there of the park, so take a look at it before you head in to the fractures.
Next, head onto the boardwalk path. This will take you down towards Almannagjá and the area of the original Icelandic parliament. It's a good cultural stop, but the fracture (Almannagjá) is a geological masterpiece.
Thingvellir National Park is an area in which the divergent plate boundary of the Mid-Atlantic Ridge, which seperates the European and North American plates, is prominent above water.
As the plates separate and pull apart, decompressed lavas erupt on the surface and form layers of basalt. The area between the plates drops down and a graben is formed.
The rocks on either side of the downdropped block are no longer held up, and therefore slowly 'peel' away from the sides, creating canyon-like fractures. Almannagjá is one of these fractures.
There are multiple other locations within the park with great sightseeing and cultural factors, so make sure to spend some time to see everything while you're there! (e.g. Öxarárfoss!)
Day 1, Site 2: After leaving Thingvellir, continue on the Golden Circle until you reach rt. 36. Drive down 36 until you reach a dirt road on the right, and follow that down until you reach a part of the road blocked off by large stones.
Park and walk down this road until you're next to a large outcrop. This is one of my personal favorites, Dagmálafjall - the picritic pillow basalt base of a 21,000-year-old tuya (see explanation here: ) (pic of picrite sample, broken and under zoom)
Take a few minutes to enjoy the outcrop. Next to it is a piece off the top of the tuya, with plenty of hyaloclastite! No samples though, please :p
Day 1, Site 3: Return to rt. 36 and head back to the main road. Turn right and continue on the Golden Circle, heading towards Geysir.
For a bit about Geysir and its history, look at this thread:
Geothermal areas are common around Iceland, and Geysir is one of the most famous. Enjoy the area, grab some lunch, and I wish you luck in getting parking!
Day 1, Site 4: Continue down the Golden Circle road and head towards Gullfoss. This is less geological in nature, but it's a great glacial river and perhaps the most impressive waterfall in Iceland.
Day 1, Site 5: After Gullfoss, get back on the Golden Circle road and return towards Geysir. You're going to turn left onto rt. 30 and head south. Next stop: Hjálparfoss.
Hjálparfoss is a bit of a drive away from Gullfoss, but the scenery to get there is beautiful. Embrace the drive as a scenic route. You may even see the elusive Hekla!
Once you arrive at Hjálparfoss, park and head down the path. The river that leads to Hjálparfoss cuts through a field of rootless cones, which are described here:
Day 1: After Hjálparfoss, continue down rt. 30 until you reach Selfoss, which will be your base camp for the night!
Day 2: Head east from Selfoss on Rt. 1. You'll be heading towards the infamous Eyjafjallajökull and Katla volcanoes! First stop: Seljalandsfoss.
Day 2, Site 1: Seljalandsfoss is a glacial waterfall originating from the Eyjafjallajökull glacier. It plunges down ancient sea cliffs, upon which waves once broke before isostatic rebound brought them 80+ meters above sea level.
Day 2, Site 2: After Seljalandsfoss, continue east to Skógafoss. This waterfall derives from Eyjafjallajökull, but also Mýrdalsjökull, which is the glacier that sits atop Katla.
You'll be able to climb to the top of Skógafoss, which also plunges from ancient sea cliffs - meaning that your car is parked in an area once underwater.
Day 2, Site 3: After Skógafoss, take a drive to the Sólheimajökull glacier, which is an outlet glacier from Mýrdalsjökull. I highly recommend taking a guided tour onto the glacier, which to this day retains ash from the Eyjafjallajökull and Grímsvötn eruptions.
Day 2, Site 4: After your glacier tour, drive down to Dyrhólaey. You'll be able to see the hole in the cliff formed from wave erosion, which, at low tide, is sometimes big enough for boats to sail through!
Day 2, Site 5: After Dyrhólaey, drive down to Reynisfjara - the infamous black sand beach next to Vík. You'll get a great, up close and personal view of columnar basalts and ocean caves, as well as the black sand formed from broken basaltic lavas.
A warning about Reynisfjara - it's notorious for 'sneaker waves', which can come high up the beach and pull unwary tourists into the ocean, after which few people are rescued and many have died.
Day 2: After Reynisfjara, head into Vík for the night for a well-deserved rest! At the right time of year, you may get a view of puffins in the area, and yet another black sand beach. (Sorry for blurry photo!)
Day 3, Stop 1: Leave Vík and continue driving east. Your next stop is a protected national monument called Dverghamrar, which gives a great view of columnar basalt, cube-jointed basalt, and the aforementioned sea level drop from isostatic rebound.
Day 3, Stop 2: After Dverghamrar, you're heading east again to the famous Skaftafell and Vatnajökull National Parks. There's lots to do here - another glacier hike, hikes to glacial moraines and till, and a waterfall (Svartifoss) that plunges through a series of basaltic columns.
Day 3, Stop 3: Next stop is Jökulsárlón, which is a lagoon full of icebergs broken from the Breiðamerkurjökull outlet glacier. These icebergs float down the lagoon and into the Atlantic Ocean.
Some of these icebergs don't make it past the breakwater and instead get stuck on the 'Diamond Beach', where pieces of ice are trapped and melt away over time.
Day 3: For the night, head to the village of Höfn. It's a fishing town famous for its langoustine (a type of lobster).
Day 4, Site 1: Go north from Höfn and into the town of Stöðvarfjörður. There, you'll find Petra's Stone Collection, which was collected over the course of one woman's dedicated life throughout the East Fjörds of Iceland.
Day 4: The east fjords are among the oldest rocks in Iceland, and there are plenty of places to stop and enjoy the scenery. Beware of reindeer crossing the road! (Another blurry photo!)
You'll have to make up your own mind on stops and sights during this portion of the drive, as the sites I would normally recommend are now closed to the public.
Stop for the night in Egilsstaðir, which is a lovely town known for its local sea monster, which lives in the neighboring lake. If you've got time and the weather permits, definitely head over the mountains to the beautiful town of Seyðisfjörður.
Day 5, Site 1: Leave Egilsstaðir and head west towards Akureyri. On the way, stop at Dettifoss, which originates from Vatnajökull, and enjoy the mist and the columnar basalts.
Day 5, Site 2: Continue west to the Krafla geothermal plant and stop by the maar lake. You'll get a great view of the 1970s flow field and the geothermal steam from the plant.
Day 5, Site 3: After the plant, cross the road to the Krafla geothermal field, where you'll get up close and personal to some mud pots and sulfurous steam.
Day 5, Site 4: Cross the mountains to Mývatn. In the area is a fracture called Grjótagjá, which contains a geothermally heated pool famous for a scene in Game of Thrones.
Day 5, Site 5: Next stop is Dimmuborgir, which is an area of volcanic pillars formed after the draining of a lava lake.
Day 5, Site 6: After Dimmuborgir is the waterfall Goðafoss, which cuts through a massive lava flow and has a cultural role in the adoption of Christianity in Iceland.
Day 5: After Goðafoss is a night spent in Akureyri, which sits at the base of a long fjord and is the northermost city in Iceland.
Day 6: Long drive today! I recommend enjoying a horseback ride beforehand, or perhaps a trip whale watching.
Continue west on Rt. 1. There are dozens of great scenic stops you can make on the way, and you'll be driving through a beautiful mountain pass. Weather dependent, you'll be taking the northern route into the town of Stykkishólmur.
Day 7, Site 1: Near the town of Stykkishólmur is a great rhyolite mountain with a large landslide, called Drápuhlíðarfjall. There's a hike you can take to the top with rhyolite slabs and Icelandic opal scattered about!
Day 7, Site 2: Next stop is my favorite lava field, Berserkjahraun. There's a drive you can take through the field, and multiple stops are possible so you can take short hikes.
This lava field is a prime example of tephra cone travelers and lava levees. Hike through on the paths and try not to get scared by the sheep (it has happened to me before...).
Day 7, Site 3: Return to Stykkishólmur and visit Haraldur Siggurdsson's Volcano Museum (Eldfjallasafn) for a tour of volcanic history through art.
Day 7: Stay in Stykkishólmur another night. Visit the island, get some Viking Sushi, and get wishes granted at the top of Helgafell.
Day 8, Site 1: Next day is a stop at the famous Kirkjufell, which has fascinating 'layercake' geology of interbedded lavas and glacial till.
Day 8, Site 2: Saxhóll, located at the end of the peninsula, is a climbable cinder cone with a great view of lavas from Snæfellsjökull and the famous Snæfellsjökull mountain itself.
Day 8, Site 3: My second favorite place in Iceland is the black pebble beach, Djúpalónssandur. Eroded basaltic pebbles are rounded from wave action, and weathered lava pillars tower above the beach.
Day 8, Site 4: The cave of Vatnshellir requires a guided tour, but the interior is well worth it - as you descend the spiral staircase, you'll be next to a lava 'waterfall'.
Day 8, Site 5: Continue around the peninsula until you reach the farm with the mineral spring Ölkelda. Pay 100 Icelandic krona and you can taste the water, which has a highly iron-rich, tonic water flavor.
Day 8: Drive to the town of Borgarnes for the night. If it's still open, drop by the Settlement Center for an education on the sagas and the settlement of the peninsula around Borgarnes.
Day 9: I added an extra day on to the schedule for 'mishaps', such as weather delays. Enjoy the area around Borgarnes. Examples:
Go climb the 2nd highest waterfall, Glymur. Visit the waterfalls Hraunfossar and Barnafoss. Visit the lava tube near Langjökull, Víðgelmir, which is the largest in Iceland. Finally, drive to Reykjavik.
Day 10: If you've got an early flight, I recommend making the stay 11 days. If you've got an afternoon flight, then leaving on day 10 is fine.
Day 10, Site 1: Drive to Kleifarvatn, which is the deepest lake in Iceland. Around this lake, there's tons of glacial tuff, laminations, ash layers, and potential striations. Not only that, but the sibling of the Egilsstaðir sea monster is rumored to live in Kleifarvatn!
Day 10, Site 2: Continuing down south, stop by the geothermal area at Krýsuvík, Seltún. It's my final favorite spot in Iceland. Lots of bubbling mud pots, hot springs, and sulfur crystals!
Day 10, Site 3: Next stop, Grænavatn, which is a lovely green maar lake. Explanation here:
Day 10, Site 4: Continue on to the town of Grindavík for lunch. I'm personally a huge fan of the lobster soup at Bryggjan!
Day 10, Site 5: To wrap up the trip, meet the divergent boundary separating North America and Europe once again at the Bridge Between the Continents.
Finally, head to the airport. If you have time or if you are staying longer, maybe stop by the Blue Lagoon! Enjoy the stay in Iceland, embrace the nature, and take lots of photos.
I hope you all enjoyed this thread and found it helpful for your next Iceland adventure :)
I hope you all enjoyed this thread and found it helpful for your next Iceland adventure :)
