This was on a river bed, where the water from the mountain comes down fiercely in the winter, so although when we were there - near Fort William - in the summer there was barely a trickle of water in the river bed, you can see from the stone that the water has worn a great dip in the stone over the years.
This tree is growing out of the rocks. It makes me think of Treebeard and the Ents pulling apart Isengard in Lord of the Rings, but in this case the tree and the rocks seem to have a very happy relationship.
We saw some wonderful eroded stone in Northumberland. The local building material is sandstone, and with the wind and the weather on the coast the sandstone has started looking like a sponge with huge holes in places. The above picture is part of the frontage of Lindisfarne Abbey and and the pillar has been worn down to a sliver.
These two stones are from Bamburgh Castle and are just full of holes. Quite extraordinary.