Those are clematis seed heads, Ad. Do you remember seeing any flowers? Pruning needs to be done according to which clematis it is, and clematis isn't my strong point. I hope someone else can advise about that.

these are the seed heads from a clematis climber. You can cut it back. Can you remember when it flowered as that will help decide the pruning regeime. If it flowered in the spring then you can prune it after flowering. the others need cutting back in the spring. {there may me better advice given for this plant after mine}

snap Beattie.

Thanks everyone. I've only recently moved in so am not sure about previous flowering. I've just added two further photographs -other parts of the plant are shown but they see to be at a different stage of development?

The extra photos seem to show at least 2 types of clematis leaves and it's quite common to plant different ones together - an early flowerer with a later one for instance.

There seems to be a pink flower in the second photo. I hope a clematis expert comes along soon to ID it for you.

The third picture looks as though it maybe clematis armandii.

I agree with beattie, there are 2 different clematis shown in these pictures. Julien is right re No 3 c. armandii - this is evergreen and group 1 pruning.
Like the others posted here so far, I don't know enough to give advice on the other.