Day Four would be spent exploring Geysir and Gulfoss. First stop was the Geysir geothermal area, where the famous Geysir (from which Geysers take their name) is situated.

The entire area is geothermally active, with steam vents dotted all around.

Geysir itself does not erupt any more - after many years of erupting with almost clockwork precision it stopped, although for a time after that it was found that by dumping 40kg of soap powder down an eruption could be triggered.

Another geyser, however, named Strokkur does still erupt at frequent intervals, to a height of up to 20 metres. The following shots show it erupting, as best is possible in a photo.

As it erupts, the water arches up into a beautiful dome, before the superheated steam bursts through.

Geysir itself sits and gently steams now, most of the time, however we were lucky enough to see it try and erupt, although it didn't actually succeed, it did make quite a concerted effort. Here we are next to it, thanks to a handily placed bench.

Also at Geysir are the twin pools of Blesi - one a brilliant, almost glowing, blue, the other crystal clear - and both very hot.

The steam surrounding the pools was enough to drench you in warm water if the wind was blowing in your direction - and also warmed nicely those of us who didn't bring a coat out from the car when it started raining.

Before we left, we watched Strokkur erupt again, this time from a different angle. The pictures below show those eruptions.

We then left Geysir, after declining to pay a huge amount of money for bad fast food, making our own sandwiches instead. We headed to Gulfoss, the largest waterfall in Iceland. As we pulled up into the car park at Gulfoss, we looked out of the window and saw the south side of the Langjökull glacier. We hadn't been expecting to see it, and seeing it bathed in sunshine (it was raining where we were) in the distance, dominating such a huge part of the horizon, was awe inspiring.

This next picture does no justice to such a beautiful sight, but it gives some impression of the scale.

After sitting and staring at the glacier for several minutes, we headed down to what we'd actually come to see - the Gulfoss waterfall. This powerful, wide waterfall consists of two major drops, totalling over 32 metres, ending at the bottom of a 70 metre deep canyon.

We headed up onto the rock outcrop pictured above (where the people are standing), and from there a better view of the lower half of the falls can be had.

This time we had to enlist the help of a real person to take our photo - here we are with the top half of Gulfoss cascading by in the background.

We headed back from Gulfoss to a place called Arnés, where our next hostel was. This was a curious place that seemed to consist of nothing but a hostel/campsite with a restaurant, swimming pool, and petrol station attached.