Need a photo or two really, but have you got a large Clematis (such as C. montana) either in your own or next door's garden, maybe one that's large enough to flower up in a tree or something? Mature Clematis montana do produce thick, woody, twined stems over the years, with the topgrowth heading off elsewhere,but this also true of any large, mature twining climber, such as Campsis radicans or others. Otherwise, need a photo...

Did it flower last year and when?, if so what were the flowers like? What was the foliage like, maybe it could be a rampant Montana, or honeysuckle or even a wisteria.

Welcome to GOY Jk1. Is this a new garden for you? It is often a good idea to wait until you see if it flowers this year before taking drastic action. I know I have seen trees in England, not so much in Scotland, being covered in ivy vines. It could be any of the suggestions already given but ivy and honeysuckle have smooth bark whereas the clematis would be more papery looking. A photo would be a great help. Don't worry if it appears on its side we can cope with that problem and someone will likely give advice on putting it up the right way.