Short UK hotel stay and treat for 10th birthday? - end of January 2017. Help!

[LilyChantilly]

For DS's 10th birthday, we'd like to take him for a long weekend to stay in a hotel somewhere that has nearby attractions which will be both open and worth visiting in January. We live in Cumbria, have a very tight budget, so needs to be near-ish, and affordable. Big towns and cities, rather than countryside, as that's what floats his boat! Hotel and attraction recommendations would be very much appreciated. Hardly ever stay in hotels, except very rarely when paid for by parents, so very little experience of them. But DS would totally love it. He has delusions of grandeur!