It really is true what they say - climbing is an expensive sport. Ah, now we get to the heart of what this is really about. After all, if you can surf the Net it's not that likely you won't be able to afford to get to or into a climbing wall. But if you're looking for a first-time introduction, then a tiny wall which is overhanging all over for bouldering superhumans won't suit. Tell me about walls then, y'sod.
Walls fall into three classes, grungiest first.
Afterthoughts put into something else, typically a leisure centre. Swansea University, where the 'wall' is actually some breeze blocks broken up and concreted into one corner of the main sports hall. No mats, no routes, no fun. Yet it's all part of a leisure centre where you can be right beside trampolinists bouncing as high as you can climb. These are intended for you to go and climb at.