It will lead you down a longish hill, with fields on either side, and Otford coming into view ahead. Perhaps you'll catch the scent of burning firewood. In Otford, you'll find more places for food and exploration. If you're historically inclined, scout the ruins of a brick palace that Henry VIII seized from the Archbishop of Canterbury. These days it's gone to seed, and that's part of the charm.
Locals walk past it and pay little attention.
But gaze up at the twinned windows of its tower and you might be able to imagine the portly Henry surveying his realm. When you've had your fill of the country, head up the hill and catch the train to London. Back in the city, you'll feel the bustle, smell the cooking fries, hear the chatter of passing teenagers. And you'll shake your head and wonder if it really is possible that just an hour earlier you were out there. Count it as another trait of London that will keep you coming back.