Great British Beach Clean, Pegwell Bay

Two hours on the sand at Pegwell Bay, litter-pickers and bags provided, doing something useful for the Marine Conservation Society's citizen-science survey while the white cliffs do their thing in the background. Children are welcome with a supervising adult.

Nobody minds if you turn up alone — that's most of who does — and it's a genuinely nice way to meet a few like-minded people while getting some sea air. Free, no booking barriers, done by lunchtime.