I visited Hardcastle Crags on the way the the Yorkshire Dales, and it was a great spot. However, on arriving on a sunny-ish Sunday afternoon at about 2:30pm, signs on the way in to the Midgehole car park stated it was full. If I'd have had an opportunity to turn around, I would have done. Luckily, I didn't, and there were in fact plenty of spaces. I was greeted by a friendly member of staff, who showed me which walks I could do. There are lots of options. I opted for the Mill walk, which took me quite high up (quite steep at times), before leading me back down to the cafe at Gibson Mill: a good reward. I then continued the walk back along the river. For those that are less keen on longer walks, you can walk along the service road to Gibson Mill from Midgehole car park too.