We left the campground at the national park and drove east toward Jökulsárlón, the glacier lagoon. On the way the size of the icecap began to show itself. Glacier tongues came down out of the mountains one after another, reaching from the high ice out onto the plain, and you started to feel how much of Vatnajökull there is behind them. The day was clear and bright.

We had met a German family at the national park the day before, a couple with their kids travelling in their own overlanding rig. We ran into them again in the car park at Jökulsárlón, and we went in to see the lagoon together.

Jökulsárlón is a lake of icebergs. The glacier behind it, Breiðamerkurjökull, an outlet of Vatnajökull, reaches down to the water and calves into it, and the broken ice floats out across the lagoon as icebergs. They drift slowly toward the sea. The lake itself is young. It did not exist before the 1930s, and it formed as the glacier retreated and left this basin behind. It is now the deepest natural lake in Iceland, about two hundred and forty-eight metres down. At the far end it narrows to a channel that runs under the ring road bridge and out to the ocean. The meltwater speeds up as it funnels into that channel, and the icebergs collect there until the current is strong enough to push them through. It is right beside the highway, the ice visible the moment you pull in, so every tourist driving the ring road stops here. It was busy. Not unbearable, but busy.

We stood with the German family and watched the ice for a while. The lagoon is the kind of place the photos do not oversell.

Then we crossed to the beach, to the black sand where the icebergs end up. The channel from the lagoon runs down to the sea and splits the beach in two, a stretch on each side. We started on the eastern side with the family. The icebergs that make it through the channel and out to sea do not all drift away. The waves push some of them back, and they wash up on the black volcanic sand and sit there, stranded. The sand is dark, almost black, and the ice on it is clear and blue and white, so the beach is scattered with lumps of ice shining against the black. That is where the name comes from, Diamond Beach.

After lunch the family were moving east, and they asked us with we wanted to join them at their next spot. We decided to bring one of our own stops forward and go along, a small change to the plan to travel with them a little. Before we left we crossed to the western side of the beach on our own. There was more ice on this side, a lot more, and some of it was big, the pieces running from the size of a fist up to blocks taller than a person. The sea works them smooth and clear, and the light comes through them. They melt where they lie, or the next tide takes them back out, so the beach is never the same twice.

We walked the ice for a while, then went back to the truck. We had a family to catch up to, and a camp to reach with them before dark.