Greenfoot Quarry

The water at Greenfoot Quarry is startlingly clear - you can see straight down to the rocky bottom, which rather explains why this flooded former quarry near Bishop Auckland has become such a draw for swimmers and kayakers over recent summers. It's a proper outdoor pool without the chlorine, though you'll want to check conditions before you go, as depth and water temperature vary significantly through the year.

The quarry itself isn't huge - you can walk the perimeter in twenty minutes - but there's something satisfying about the sheer faces and the way the water just stops being that vivid blue and turns dark where it gets deep. Families tend to come early in the day or on weekdays to avoid crowds; teenagers and braver types show up for the jumping spots along the higher edges. Swimming here is genuinely free, though how "official" it is remains unclear, so treat it as the kind of place where you use common sense and check before you leap.

If you're based at Greenfoot Holiday Home Park itself - literally two minutes' walk away - this becomes an obvious morning activity. For those at Belle Vue Farm near Stanhope or further afield at Heather View, it's worth a short drive. Allow an hour if you're just swimming, longer if you've brought a picnic and want to linger. The site can get busy on sunny weekends, so aim for quieter times if you prefer space to yourself. It's brilliant for teenagers but less engaging for younger children who can't yet swim confidently.