Even on a tight schedule, Bray to Greystones Cliff Walk earns the hours.
Allow Half day (3–4 hours).
A rewarding, mostly-flat clifftop walk with constant sea views, easily turned into a half-day with a DART out and back. The honest catch: it's a committed 2–2.5 hour walk fully exposed to the weather, with little shade or shelter, so it's miserable in wind or rain and a slog for the unfit.