At four o'clock this morning, some of the other inhabitants of this apartment were getting ready to depart for the airport. This I deduce from the noise of a suitcase being dragged over a tiled floor. At five o'clock the people in room 6 left. By about 6.30 I'd given up on sleep and was starting to get stuff together for the day.

First there was the interesting discovery that my Thursday blog - the day I didn't do anything except arrive! - was OffExploring's Blog of the Day. Then there was breakfast and packing. I decided to take my boots, if only to make today's guide happy so I tied the laces nicely together and went out to stand on the street.

We weren't in the truck today. We were in its big brother, the coach version. It's a smallish coach but it's still a coach, a 40-seater according to Grayline's website. We had a driver (Andreas) and a guide (Gir) instead of a driver-guide. Gir talked non-stop all the way to our first stop and I took notes. Many many notes. The mountains between Reykjavík and Hveragerði are called the Blue Mountains and they supply Reykjvakík's drinking water. In fact, they supply enough water for 1.5 million people. The entire population of Iceland is only 320,000, of which 60-70% live in the capital. Enlarge that to within a 35 mile radius of the capital and 80-83% of the population live there. The Blue Mountains are only 10,000 years old which is very young by geological standards. The geological power plant at Hengill has the same output as your average nuclear power station and could supply power for 3 or 4 cities the size of Reykjavík. Only 10% of its energy goes to the public, the other 90% goes to industry, mostly production of aluminium. Gir thinks that the theoretical energy of Iceland - if they used every river, every waterfall, every volcano to get as much geothermal and hydro energy as physically possible, they could power the entire USA, which uses around 1.5 million megawatts per year, whereas Iceland only gets through about 2300.

We were at Hveragerði by now (I have condensed his speech quite a lot). The second biggest ice cream factory in Iceland is there and the first greenhouse was built in 1937. During the war, there was a big runway just over the fields from the town, the second biggest in Europe at the time. It's now gone but people like Churchill used it fairly regularly. A reporter once asked him what the most unusual thing was he'd eaten on his travels and I could feel what the answer was going to be. Gir dragged it out and finally, there were the magic words "Icelandic bananas", from the greenhouses at Hveragerði.

Next was the long tedious drive over the farmland. I had noticed that you could see Eyjafjalljökull and the Westman Islands from as far away as the hilltop before Hveragerði and yet half an hour later, Gir still hadn't mentioned the volcano. It was coming. Eyjafjalljökull threw out 2000 tons of ash per second during its 2010 eruption. Grimsvötn, a bigger volcano which erupted in 2011 threw out 20,000 tons of ash per second but it didn't cause air traffic chaos so hardly anyone outside Iceland noticed. Apparently the reason Eyjafjalljökull's was so massive was "because old magma is like milk". The theory is that magma that sits in the magma chamber for a long time goes sour and becomes more acidic. Then fresh magma rises up, meets the old stuff and the whole thing explodes. It meets the glacier on top and there's ash and explosions and chaos.

Hekla, on the other hand, a bigger, more evil one to the north of Eyjafjallajökull, and overdue, is more like a sponge. Apparently you can tell its magma chamber is more full than it was before its last eruption (February 2000) because it's blowing up like a balloon. It just sucks in water and soon the magma will touch that water and the whole thing will explode. It's explosive at first, then it settles down and just spills out a lot of lava, which the Icelandics like because it's pretty and it attracts tourists. Apparently last time Hekla went up, once it was over the ash phase, most of the population of Reykjavík went to see it erupt, only to get caught in a snowstorm on the slopes which meant a massive rescue effort to get over 1000 people off the volcano. In another eruption a man standing outside the church at Skálholt 50km away got hit by a rock from Hekla. Not killed, just maybe knocked out. Hekla is the most active volcano in Iceland. Volcanologists can just about manage a 30 minute warning before she erupts and there's no real crater on her, the explosion can come from anywhere on the mountain. That's pretty much the end of the speech.

By now we'd made our first "technical stop" at Árnes and were on our way towards the Interior. The road soon ran out and we were on gravel. Less bumpy than yesterday and to our first proper stop - a double waterfall called Hjálparfoss. That was spectacular. They were quite low but fairly wide and very pretty and surrounded by basalt cliffs. I've never seen basalt hexagons before but I was under the impression they're usually vertical columns. These were horizontal. Beyond that, the river wound its way down to a hydro-electric power station.

After that it was just wilderness. Rocks and lava fields and rivers and lakes and nothing. It was spectacular in a moon-like way. I was confused by some columns of steam on the other side of a river for a while. I couldn't figure out what they were or why they were there or why they seemed to be moving and after staring at them forever, I realised it was dust being sent up by a car whizzing along the gravel road.

The drive went on forever and got pretty uncomfortable. I began to wish I was off the bus and at Landmannalaugar already. We went round lakes, over small canyons on bridges that seemed much to narrow and at too high a speed. Gir talked about outlaws and Viking law and banishment and this place really was like being on the moon.

We made our second "technical stop" at Hrauneyjar - one of my favourite names because "Hraun" means the lava plains and "eyjar" means island - so this little stop was the island in the middle of the lava. I had a look at a map and decided we must be pretty close by now. I was wrong. We had another hour and a half and it was the worst bit.

The road seemed to vanish altogether and we had to go up and down slopes - scary enough in a car probably but terrifying in a coach. It was getting painfully bumpy and completely bare - there just aren't the words to describe how utterly dead and bare and desolate the Icelandic Highlands are. Mile after mile of bumpy roadless grey nothing.

We stopped for a quick leg-stretch on the edge of a crater filled with blue-green water. Absolutely spectacular and I began to feel like maybe it was worth the effort of the journey - because sitting still on a coach that thinks it's a kangaroo is surprisingly hard work. There was a slope up to the crater and then of course a slope back down. Partway down I realised that everyone on the entire coach was swaying side to side in exactly the same way and got the giggles, so of course I had to video that.

We still weren't there and the roads were getting worse still. We had hairpins now and we had to reverse up a hairpin to let a car go past. I am a little bit nervous of manoeuvres like that. Then we came across some ATVs, part of the voluntary rescue services. There are 18000 people in rescue groups across Iceland, 3000 ready to go at any given time. The Landmannalaugar road - I say road! - is only open for 6-8 weeks each year and during that time, they get around 1000 requests for help. That's around 20 every single day.

Now we really were getting close. We rounded a bend and there were those spectacular steadky rhyolite mountains that I'd wanted to see so much. There was still the ford to contend with. My guidebook says:

In good conditions skilled drivers might be able to nurse a conventional vehicle to the ford at Landmannalaugar, the passengers then hitching a ride across with something more sturdy, but you're not advised to try.

Quite why you need to hitch a ride across the ford is beyond me as it's all of a five minute walk from the campsite and there are footbridges over the water. But it did mean a lot of vehicles parked at a distance. We splashed straight through the ford - the coach may be bigger than the truck but it's just as tough.

We had less than two hours at Landmannalaugar after a four hour drive to get there. I spent the first three quarters of an hour getting to and in the hot springs. Steaming hot water rises up from under the lava field and flows into a cool stream. You jump on in and paddle around until you find somewhere the right temperature. Right up by the springs can be painfully hot but even if you paddle downstream to the cooler bits, bubbles of hot water still pop up and you can suddenly find you've had your foot on something incredibly hot. Also no one mentions that it's full of floating weedy algae stuff, which is revolting. Worth putting up with as a novelty but I prefer my steaming hot baths without green gunk.

It was a very nice location for a wild swim. I made a friend who took photos of me, although he was determined for me to take off my sunglasses which meant I couldn't see anything and the sun was painfully bright, so the glassesless photos are pretty bad. I sploshed around in the unnaturally warm water for a while and then decided regretfully that I really did have to get out, get dressed and go and visit those mountains.

On the way I ran into some Icelandic horses, who were friendly enough and happy to have their noses stroked and then I made my way out onto the plain to stare at the streaky mountains for a while. By then I only had forty minutes of our precious time left so I took as many photos as I could and headed to my right to the canyon.

I wish I'd had more time to explore that canyon. We really could have done with leaving even earlier and staying overnight. It was great to see the Highlands, really other-wordly, but I came out to see Landmannalaugar. The Green Canyon is certainly greenish and it has a little river running through it. Guess who couldn't resist a paddle? My boots, of course, stayed on the bus.

Then it was back to the site to find the coach, take a couple of last photos of the beautiful mountains and head out again. We would follow the same track back to the big lake and then go a different way. We'd come in from the north on F208, the new road built to go with the new power line. We would be going out to the west on the old F 225, the sheep-gathering route.

The mountains this way were generally a little bit greener and there were a lot more river crossings. The track was more track-like but it was also bumpier. I was aching from the hours and hours of bumpy driving and things kept falling off the seats because they got bounced off. At one point I sat up to try and stretch out the aches and realised that my boots had walked all by themselves into the aisle and managed to injure my shoulder retrieving them.

Five minutes later we stopped at the roadside to see Hekla closer up and I managed to injure my wrist jumping out of the bus. It was not a good afternoon. The ground, made up of stuff thrown from Hekla in various eruptions, was black and had a weird texture, sort of crunchy. I took photos, I borrowed a formation to use as a tripod to take a self-timing photo and then it occurred to me to have a look at what I was actually walking on. It seemed to be pumice. I liberated a few tiny bits to bring home and when we got back on the coach, it seemed everyone had brought a souvenir, mostly bigger pieces than mine.

More bumping. Everyone was falling asleep, although how they could sleep when the road conditions were like that and when there was Icelandic scenery around them I don't know. It felt amazing to be back on paved road at last. We whizzed down the nice smooth flat road and made our final "technical stop" of the day. I looked up from my guidebook and almost squeaked out loud. We'd stopped at a small random petrol station in the middle of nowhere - and it happened to be the one we'd hunted for the Northern Lights at last year. It was nice to see it in daylight. In fact, it was nice to see it again - I'd never expected that. I'd seen a massive orange moonrise from behind it and before I'd realised what it was, I'd thought it was maybe a volcano in the distance. I now discovered that Hekla - an overdue volcano - sits more or less exactly where the moon was rising. You can also see Eyjafjalljökull and the Westman Islands from there, so it has a surprisingly good view when you're not there in pitch blackness. I managed to finally put it down on a map - it's on the junction of the 1 and the 26 and is described in my guidebook as "a lone petrol station".

Then it was back along the ring road, on the now very familiar route through Selfoss, Hveragerði, Blue Mountains and down into Reykjavík. We got back about 6.45pm and I went shopping on my way home. First I stuck my head in all the tourist shops along Laugavegur and then went back along Hverfisgata to the underfloor-heated Austurstræti for some food. Just some chocolate milk and bread rolls and the nice lady in the shop helped herself to all the coins in my wallet. That doesn't sound nice but I've built up a ridiculous collection of change and the coins are such small value and I'm still so bad at recognising them that they're hard to spend. Today I opened my wallet to stare at them a little bit helplessly and the lady just picked out all the bits I needed and lightened it considerably. When a coin worth half a penny is the size of a UK 10p, it's very helpful to get rid of a few occasionally.

And then I was done for the day. Tomorrow should be much shorter. I don't get picked up until 9.15 or even 9.30 and the duration is only supposed to be 5-6 hours. I make up for it on Monday with a massive 16 hour trip to Vatnajökull, which is about twice the distance to Þórsmörk, when I imagine I'll get home around midnight.