I am planning a route through mid-Wales and so far I've been able to find campgrounds for all nights except for the vicinity around Nant-Y-Moch reservoir (10km radius, give or take).

Any recommendations for where to look (or where to avoid) for suitable wild camping spots? Any thoughts on wild camping etiquette / when or where to ask permission for this region?

Thanks.

The world is very much you oyster in that vacinity. Although, asking the landowners permission is the correct thing to do, often it simply isn't practical and this is a point in case - arrive late, leave early and obviously LNT (that includes not lighting fires) and you'll be fine.

I'll send you a PM with some grid references on.

Thank you! Very much appreciated!