Lullingstone Country Park

The River Darent cuts through a proper slice of Kent countryside here, and Lullingstone gives you access to some genuinely lovely riverside walking without the crowds you'd get at more famous spots closer to London. The park sits just outside Sevenoaks and spreads across meadows and woodland that actually feel removed from the southeast sprawl, even though you're barely half an hour from the M25.

You're looking at a few miles of marked paths through mixed woodland and along the river itself - nothing strenuous, nothing that demands fell boots, but enough to stretch your legs properly. The best bit is reaching the open meadow sections where you can actually see the water and spot kingfishers if you're lucky and quiet. It's the sort of place where families can manage a decent two-hour walk without anyone complaining, and older kids won't find it boring because there's enough wildlife interest to keep them engaged.

The park runs into Thriftwood Country Park just a few miles away, so if you're basing yourself at one of the local caravan sites, you could easily do both in a week without repetition. Spring's probably your best bet for wildflowers, and autumn when the light's golden through the trees. Free to access, as most country parks are in Kent, and you can spend as long as you like wandering about. Car park by the main entrance gets busy on weekends, so aim for midweek if possible.