This play of colours continued for half an hour, then faded gradually till it vanished entirely, and the ordinary atmosphere took its place.

It was one of the most beautiful appearances I had ever witnessed.
June 25th.
The roads separate about a mile behind the little town of Thingvalla; the one to the left goes to Reikholt, the right-hand one leads to the Geyser.
We rode for some time along the shores of the lake, and found at the end of the valley an awful chasm in the rock, similar to the one of Almanagiau, which we had passed on such a wretched road.
The contiguous valley bore a great resemblance to that of Thingvalla; but the third one was again fearful.

Lava covered it, and was quite overgrown with that whitish moss, which has a beautiful appearance when it only covers a portion of the lava, and when black masses rise above it, but which here presented a most monotonous aspect.
We also passed two grottoes which opened at our feet.

At the entrance of one stood a pillar of rock supporting an immense slab of lava, which formed an awe-inspiring portal.

I had unfortunately not known of the existence of these caves, and was consequently unprepared to visit them.
Torches, at least, would have been requisite.