Length: 14 km (8.7 miles). Toughness: 3/10
10:13 Sevenoaks train from Blackfriars, calling at almost every station in south London and arriving Eynsford at 11:06. Buy a return to Eynsford (from St Mary Cray if you've also got a Zones 1-6 Travelcard; from Swanley if you've got a Freedom Pass).
If it's more convenient you can take the 10:12 Rochester train from Victoria and change onto the Sevenoaks train at Bromley South or Swanley, but there's a 15-minute wait so it's no quicker.
Trains back from Eynsford to Blackfriars are half-hourly at xx:11 & xx:41. Change at Bromley South if you want to return to Victoria.
This is notionally a ‘new’ walk in the Darent valley, but regulars will soon twig that it's a reworking of parts of the Farningham Road to Eynsford walk. It has rather too many tarmac stretches on the return leg but that might be no bad thing in winter. I'm also proposing the option which omits the potentially muddy woods in Lullingstone Park. Towards the end the walk goes through Eynsford village (bypassed on other SWC walks) where you might be able to explore the ruins of Eynsford Castle (free entry, if open).
I heard some grumbling about the lack of cider and chips when I recently posted a Sunday walk without a pub at the lunch stop. In order to atone for this deplorable faux pas there are three possible lunch pubs on this walk (one of which you go past twice), plus two or three more at the end in Eynsford.
You might find it hard to resist the temptation to stop at the first pub since the route goes right through the riverside beer garden of the Lion Hotel in Farningham, but the one closest to the walk's midpoint is the Fighting Cocks in Horton Kirby. As always, it's advisable to book if you want to be sure of something more than a bowl of chips. Both have picnic areas nearby if you prefer to bring your own provisions.
At the end of the walk there are three pubs in Eynsford, although sadly the Riverside Tea Room seems to have permanently closed.
You'll need to bring the directions from the L=swc.419.a page. If you're printing them from this page you can save a couple of sheets of paper by first clicking ‘Short Walk 1’ in Walk Options.