Brecon Beacons Mountain Walk
This is a fantastic walk but one which I have not often repeated due to the difficulty of finding it. You start off through a wooded area, then head across open countryside towards snow capped mountains, with a stream on your left that initiially is quite large, but as you get higher into the hills, it diminishes so you are eventually able to cross it.
The return walk down the other side of the valley takes you on a barely marked sheep path through open mountainside with views all around, until you eventually descend, keeping the stream/ river in sight on your left. Do not bother trying to cross the stream to get back on to your outward bound path. I tried this the first time but it was not easy to cross. You don't need to anyway.
As you continue heading downstream, you will descend into an area of bushes and higher ferns, with a barbed wire fence on your left ("civilisation", you breathe with relief!). You cross through a sheep field, through a field gate onto a private stoney lane, eventually finding a footpath sign down a private drive going off to the left off the lane you are now on. Follow the drive looking for the footpath sign over a style, and you go through a series of further fields heading in the general direction of the car park. Provided you have a good nose to sense your direction, and an awareness of which mountain tops you parked near, you will turn left at the right path to get back through the same wooded area you initially headed through at the start, and thus return to the car park.
However you do need a good sense of direction to do this walk as you are on your own, in remote territory.